VB.Net Tutorial/GUI/TextBox Validation

TextBox validating event

Imports System.Windows.Forms
public class TextBoxValidating
   public Shared Sub Main
        Application.Run(New Form1)
   End Sub
End class
Public Class Form1
    Inherits System.Windows.Forms.Form
#Region " Windows Form Designer generated code "
    Public Sub New()
        MyBase.New()
        "This call is required by the Windows Form Designer.
        InitializeComponent()
        "Add any initialization after the InitializeComponent() call
    End Sub
    "Form overrides dispose to clean up the component list.
    Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
        If disposing Then
            If Not (components Is Nothing) Then
                components.Dispose()
            End If
        End If
        MyBase.Dispose(disposing)
    End Sub
    "Required by the Windows Form Designer
    Private components As System.ruponentModel.IContainer
    "NOTE: The following procedure is required by the Windows Form Designer
    "It can be modified using the Windows Form Designer.  
    "Do not modify it using the code editor.
   Friend WithEvents Label1 As System.Windows.Forms.Label
   Friend WithEvents txtInput As System.Windows.Forms.TextBox
   Friend WithEvents Label2 As System.Windows.Forms.Label
   Friend WithEvents Label3 As System.Windows.Forms.Label
   Friend WithEvents lblTrue As System.Windows.Forms.Label
   Friend WithEvents lblCheck As System.Windows.Forms.Label
   Friend WithEvents lblResults As System.Windows.Forms.Label
   Friend WithEvents btnClear As System.Windows.Forms.Button
    <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
Me.Label1 = New System.Windows.Forms.Label()
Me.txtInput = New System.Windows.Forms.TextBox()
Me.Label2 = New System.Windows.Forms.Label()
Me.Label3 = New System.Windows.Forms.Label()
Me.lblTrue = New System.Windows.Forms.Label()
Me.lblCheck = New System.Windows.Forms.Label()
Me.lblResults = New System.Windows.Forms.Label()
Me.btnClear = New System.Windows.Forms.Button()
Me.SuspendLayout()
"
"Label1
"
Me.Label1.Font = New System.Drawing.Font("Tahoma", 14.25!, (System.Drawing.FontStyle.Bold Or System.Drawing.FontStyle.Italic), System.Drawing.GraphicsUnit.Point, CType(0, Byte))
Me.Label1.Location = New System.Drawing.Point(48, 16)
Me.Label1.Name = "Label1"
Me.Label1.Size = New System.Drawing.Size(176, 23)
Me.Label1.TabIndex = 0
Me.Label1.Text = "ISBN Validation"
"
"txtInput
"
Me.txtInput.Location = New System.Drawing.Point(72, 64)
Me.txtInput.Name = "txtInput"
Me.txtInput.TabIndex = 1
Me.txtInput.Text = ""
"
"Label2
"
Me.Label2.Location = New System.Drawing.Point(24, 104)
Me.Label2.Name = "Label2"
Me.Label2.Size = New System.Drawing.Size(80, 23)
Me.Label2.TabIndex = 2
Me.Label2.Text = "True Number:"
"
"Label3
"
Me.Label3.Location = New System.Drawing.Point(32, 152)
Me.Label3.Name = "Label3"
Me.Label3.Size = New System.Drawing.Size(72, 23)
Me.Label3.TabIndex = 3
Me.Label3.Text = "Check Digit:"
"
"lblTrue
"
Me.lblTrue.BorderStyle = System.Windows.Forms.BorderStyle.Fixed3D
Me.lblTrue.Location = New System.Drawing.Point(112, 104)
Me.lblTrue.Name = "lblTrue"
Me.lblTrue.TabIndex = 4
"
"lblCheck
"
Me.lblCheck.BorderStyle = System.Windows.Forms.BorderStyle.Fixed3D
Me.lblCheck.Location = New System.Drawing.Point(112, 152)
Me.lblCheck.Name = "lblCheck"
Me.lblCheck.TabIndex = 5
"
"lblResults
"
Me.lblResults.Location = New System.Drawing.Point(56, 192)
Me.lblResults.Name = "lblResults"
Me.lblResults.Size = New System.Drawing.Size(152, 24)
Me.lblResults.TabIndex = 6
"
"btnClear
"
Me.btnClear.Location = New System.Drawing.Point(88, 240)
Me.btnClear.Name = "btnClear"
Me.btnClear.TabIndex = 7
Me.btnClear.Text = "Clear"
"
"Form1
"
Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
Me.ClientSize = New System.Drawing.Size(264, 293)
Me.Controls.AddRange(New System.Windows.Forms.Control() {Me.btnClear, Me.lblResults, Me.lblCheck, Me.lblTrue, Me.Label3, Me.Label2, Me.txtInput, Me.Label1})
Me.Name = "Form1"
Me.Text = "ISBN Validation"
Me.ResumeLayout(False)
    End Sub
#End Region
 
   Private Sub IsbnValidation(ByVal sender As Object, ByVal e As System.ruponentModel.CancelEventArgs) Handles txtInput.Validating
         Console.WriteLine("validating")
   End Sub
   Private Sub btnClear_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnClear.Click
      txtInput.Text = ""
      lblResults.Text = ""
      lblTrue.Text = ""
      lblCheck.Text = ""
   End Sub
   Private Sub txtInput_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles txtInput.KeyPress
      Dim keyChar As Char
      keyChar = e.KeyChar
      
      " Suppress any keys except digits,X,x,hyphen (45),Backspace (8),or Enter (13)
      If ((Not Char.IsDigit(keyChar)) _
         And (AscW(keyChar) <> 8) _
         And (AscW(keyChar) <> 13) _
         And (keyChar <> "X"c) _
         And (keyChar <> "x"c) _
         And (AscW(keyChar) <> 45)) Then
         "  Do not display the keystroke
         e.Handled = True
      End If
   End Sub
End Class

TextField validation: cannot be empty

Imports System.Text.RegularExpressions
Imports System.Windows.Forms
public class AddressValidationNotEmpty
   public Shared Sub Main
        Application.Run(New Address)
   End Sub
End class
Public Class Address
  Inherits System.Windows.Forms.Form

#Region " Windows Form Designer generated code "
  Public Sub New()
    MyBase.New()
    "This call is required by the Windows Form Designer.
    InitializeComponent()
    "Add any initialization after the InitializeComponent() call
  End Sub
  "Form overrides dispose to clean up the component list.
  Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
    If disposing Then
      If Not (components Is Nothing) Then
        components.Dispose()
      End If
    End If
    MyBase.Dispose(disposing)
  End Sub
  Friend WithEvents Label3 As System.Windows.Forms.Label
  Friend WithEvents Label4 As System.Windows.Forms.Label
  Friend WithEvents Label5 As System.Windows.Forms.Label
  Friend WithEvents lblStreet As System.Windows.Forms.Label
  Friend WithEvents txtStreet As System.Windows.Forms.TextBox
  Friend WithEvents txtState As System.Windows.Forms.TextBox
  Friend WithEvents txtCountry As System.Windows.Forms.TextBox
  Friend WithEvents lblCity As System.Windows.Forms.Label
  Friend WithEvents btnCancel As System.Windows.Forms.Button
  Friend WithEvents txtZip As System.Windows.Forms.TextBox
  Friend WithEvents txtCity As System.Windows.Forms.TextBox
  Friend WithEvents btnOK As System.Windows.Forms.Button
  Friend WithEvents errAddress As System.Windows.Forms.ErrorProvider
  Friend WithEvents ToolTip1 As System.Windows.Forms.ToolTip
  Private components As System.ruponentModel.IContainer
  "Required by the Windows Form Designer
  "NOTE: The following procedure is required by the Windows Form Designer
  "It can be modified using the Windows Form Designer.  
  "Do not modify it using the code editor.
  <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
    Me.ruponents = New System.ruponentModel.Container()
    Me.ToolTip1 = New System.Windows.Forms.ToolTip(Me.ruponents)
    Me.txtCountry = New System.Windows.Forms.TextBox()
    Me.Label4 = New System.Windows.Forms.Label()
    Me.Label5 = New System.Windows.Forms.Label()
    Me.txtCity = New System.Windows.Forms.TextBox()
    Me.Label3 = New System.Windows.Forms.Label()
    Me.txtZip = New System.Windows.Forms.TextBox()
    Me.btnOK = New System.Windows.Forms.Button()
    Me.lblCity = New System.Windows.Forms.Label()
    Me.btnCancel = New System.Windows.Forms.Button()
    Me.txtState = New System.Windows.Forms.TextBox()
    Me.txtStreet = New System.Windows.Forms.TextBox()
    Me.errAddress = New System.Windows.Forms.ErrorProvider()
    Me.lblStreet = New System.Windows.Forms.Label()
    Me.SuspendLayout()
    "
    "txtCountry
    "
    Me.txtCountry.Location = New System.Drawing.Point(88, 64)
    Me.txtCountry.Name = "txtCountry"
    Me.txtCountry.Size = New System.Drawing.Size(112, 20)
    Me.txtCountry.TabIndex = 4
    Me.txtCountry.Text = "txtCountry"
    "
    "Label4
    "
    Me.Label4.AutoSize = True
    Me.Label4.CausesValidation = False
    Me.Label4.Location = New System.Drawing.Point(208, 68)
    Me.Label4.Name = "Label4"
    Me.Label4.Size = New System.Drawing.Size(42, 13)
    Me.Label4.TabIndex = 10
    Me.Label4.Text = "Zip/PC:"
    "
    "Label5
    "
    Me.Label5.AutoSize = True
    Me.Label5.CausesValidation = False
    Me.Label5.Location = New System.Drawing.Point(232, 44)
    Me.Label5.Name = "Label5"
    Me.Label5.Size = New System.Drawing.Size(60, 13)
    Me.Label5.TabIndex = 11
    Me.Label5.Text = "State/Prov:"
    "
    "txtCity
    "
    Me.txtCity.Location = New System.Drawing.Point(88, 40)
    Me.txtCity.Name = "txtCity"
    Me.txtCity.Size = New System.Drawing.Size(136, 20)
    Me.txtCity.TabIndex = 2
    Me.txtCity.Text = "txtCity"
    "
    "Label3
    "
    Me.Label3.AutoSize = True
    Me.Label3.CausesValidation = False
    Me.Label3.Location = New System.Drawing.Point(8, 68)
    Me.Label3.Name = "Label3"
    Me.Label3.Size = New System.Drawing.Size(47, 13)
    Me.Label3.TabIndex = 9
    Me.Label3.Text = "Country:"
    "
    "txtZip
    "
    Me.txtZip.Location = New System.Drawing.Point(264, 64)
    Me.txtZip.Name = "txtZip"
    Me.txtZip.Size = New System.Drawing.Size(96, 20)
    Me.txtZip.TabIndex = 1
    Me.txtZip.Text = "txtZip"
    "
    "btnOK
    "
    Me.btnOK.DialogResult = System.Windows.Forms.DialogResult.OK
    Me.btnOK.Location = New System.Drawing.Point(200, 96)
    Me.btnOK.Name = "btnOK"
    Me.btnOK.TabIndex = 5
    Me.btnOK.Text = "OK"
    "
    "lblCity
    "
    Me.lblCity.AutoSize = True
    Me.lblCity.CausesValidation = False
    Me.lblCity.Location = New System.Drawing.Point(8, 44)
    Me.lblCity.Name = "lblCity"
    Me.lblCity.Size = New System.Drawing.Size(27, 13)
    Me.lblCity.TabIndex = 8
    Me.lblCity.Text = "City:"
    "
    "btnCancel
    "
    Me.btnCancel.CausesValidation = False
    Me.btnCancel.DialogResult = System.Windows.Forms.DialogResult.Cancel
    Me.btnCancel.Location = New System.Drawing.Point(285, 96)
    Me.btnCancel.Name = "btnCancel"
    Me.btnCancel.TabIndex = 6
    Me.btnCancel.Text = "Cancel"
    "
    "txtState
    "
    Me.txtState.Location = New System.Drawing.Point(296, 40)
    Me.txtState.Name = "txtState"
    Me.txtState.Size = New System.Drawing.Size(64, 20)
    Me.txtState.TabIndex = 3
    Me.txtState.Text = "txtState"
    "
    "txtStreet
    "
    Me.txtStreet.Location = New System.Drawing.Point(88, 16)
    Me.txtStreet.Name = "txtStreet"
    Me.txtStreet.Size = New System.Drawing.Size(272, 20)
    Me.txtStreet.TabIndex = 0
    Me.txtStreet.Text = "txtStreet"
    "
    "errAddress
    "
    Me.errAddress.DataMember = Nothing
    "
    "lblStreet
    "
    Me.lblStreet.AutoSize = True
    Me.lblStreet.CausesValidation = False
    Me.lblStreet.Location = New System.Drawing.Point(8, 20)
    Me.lblStreet.Name = "lblStreet"
    Me.lblStreet.Size = New System.Drawing.Size(38, 13)
    Me.lblStreet.TabIndex = 7
    Me.lblStreet.Text = "Street:"
    "
    "Address
    "
    Me.AcceptButton = Me.btnOK
    Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
    Me.CancelButton = Me.btnCancel
    Me.ClientSize = New System.Drawing.Size(378, 137)
    Me.Controls.AddRange(New System.Windows.Forms.Control() {Me.Label5, Me.Label4, Me.Label3, Me.lblCity, Me.lblStreet, Me.btnCancel, Me.btnOK, Me.txtCountry, Me.txtState, Me.txtCity, Me.txtZip, Me.txtStreet})
    Me.FormBorderStyle = System.Windows.Forms.FormBorderStyle.FixedDialog
    Me.MaximizeBox = False
    Me.MinimizeBox = False
    Me.Name = "Address"
    Me.Text = "Address"
    Me.ResumeLayout(False)
  End Sub
#End Region
  Private Sub GenericNotEmpty(ByVal sender As Object, _
  ByVal e As System.ruponentModel.CancelEventArgs) _
  Handles txtStreet.Validating, txtCity.Validating, _
    txtState.Validating
    Dim ctlSender As Control
    ctlSender = CType(sender, Control)
    If ctlSender.Text.Trim = "" Then
      e.Cancel = True
      errAddress.SetError(ctlSender, "Must not be empty")
    End If
  End Sub
End Class

Validate user information using regular expressions.

Imports System.Windows.Forms
Imports System.Text.RegularExpressions
public class RegxValidateTextBox
   public Shared Sub Main
        Application.Run(New FrmValid)
   End Sub
End class


Public Class FrmValid
   Inherits System.Windows.Forms.Form
#Region " Windows Form Designer generated code "
   Public Sub New()
      MyBase.New()
      "This call is required by the Windows Form Designer.
      InitializeComponent()
      "Add any initialization after the InitializeComponent() call
   End Sub
   "Form overrides dispose to clean up the component list.
   Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
      If disposing Then
         If Not (components Is Nothing) Then
            components.Dispose()
         End If
      End If
      MyBase.Dispose(disposing)
   End Sub
   Friend WithEvents txtState As System.Windows.Forms.TextBox
   Friend WithEvents txtLast As System.Windows.Forms.TextBox
   Friend WithEvents txtFirst As System.Windows.Forms.TextBox
   Friend WithEvents lblZip As System.Windows.Forms.Label
   Friend WithEvents lblPhone As System.Windows.Forms.Label
   Friend WithEvents lblLast As System.Windows.Forms.Label
   Friend WithEvents lblFirst As System.Windows.Forms.Label
   Friend WithEvents lblAddress As System.Windows.Forms.Label
   Friend WithEvents txtAddress As System.Windows.Forms.TextBox
   Friend WithEvents txtZip As System.Windows.Forms.TextBox
   Friend WithEvents txtCity As System.Windows.Forms.TextBox
   Friend WithEvents lblCity As System.Windows.Forms.Label
   Friend WithEvents lblState As System.Windows.Forms.Label
   Friend WithEvents txtPhone As System.Windows.Forms.TextBox
   Friend WithEvents cmdOK As System.Windows.Forms.Button
   "Required by the Windows Form Designer
   Private components As System.ruponentModel.Container
   "NOTE: The following procedure is required by the Windows Form Designer
   "It can be modified using the Windows Form Designer.  
   "Do not modify it using the code editor.
   <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
      Me.txtState = New System.Windows.Forms.TextBox()
      Me.txtLast = New System.Windows.Forms.TextBox()
      Me.txtFirst = New System.Windows.Forms.TextBox()
      Me.lblZip = New System.Windows.Forms.Label()
      Me.lblPhone = New System.Windows.Forms.Label()
      Me.lblLast = New System.Windows.Forms.Label()
      Me.lblFirst = New System.Windows.Forms.Label()
      Me.lblAddress = New System.Windows.Forms.Label()
      Me.txtAddress = New System.Windows.Forms.TextBox()
      Me.txtZip = New System.Windows.Forms.TextBox()
      Me.txtCity = New System.Windows.Forms.TextBox()
      Me.lblCity = New System.Windows.Forms.Label()
      Me.lblState = New System.Windows.Forms.Label()
      Me.txtPhone = New System.Windows.Forms.TextBox()
      Me.cmdOK = New System.Windows.Forms.Button()
      Me.SuspendLayout()
      "
      "txtState
      "
      Me.txtState.Location = New System.Drawing.Point(100, 170)
      Me.txtState.Name = "txtState"
      Me.txtState.Size = New System.Drawing.Size(136, 20)
      Me.txtState.TabIndex = 4
      Me.txtState.Text = ""
      "
      "txtLast
      "
      Me.txtLast.Location = New System.Drawing.Point(100, 30)
      Me.txtLast.Name = "txtLast"
      Me.txtLast.Size = New System.Drawing.Size(136, 20)
      Me.txtLast.TabIndex = 0
      Me.txtLast.Text = ""
      "
      "txtFirst
      "
      Me.txtFirst.Location = New System.Drawing.Point(100, 65)
      Me.txtFirst.Name = "txtFirst"
      Me.txtFirst.Size = New System.Drawing.Size(136, 20)
      Me.txtFirst.TabIndex = 1
      Me.txtFirst.Text = ""
      "
      "lblZip
      "
      Me.lblZip.Location = New System.Drawing.Point(10, 205)
      Me.lblZip.Name = "lblZip"
      Me.lblZip.Size = New System.Drawing.Size(80, 24)
      Me.lblZip.TabIndex = 13
      Me.lblZip.Text = "Zip"
      Me.lblZip.TextAlign = System.Drawing.ContentAlignment.MiddleRight
      "
      "lblPhone
      "
      Me.lblPhone.Location = New System.Drawing.Point(10, 240)
      Me.lblPhone.Name = "lblPhone"
      Me.lblPhone.Size = New System.Drawing.Size(80, 24)
      Me.lblPhone.TabIndex = 14
      Me.lblPhone.Text = "Phone"
      Me.lblPhone.TextAlign = System.Drawing.ContentAlignment.MiddleRight
      "
      "lblLast
      "
      Me.lblLast.Location = New System.Drawing.Point(10, 30)
      Me.lblLast.Name = "lblLast"
      Me.lblLast.Size = New System.Drawing.Size(80, 24)
      Me.lblLast.TabIndex = 8
      Me.lblLast.Text = "Last Name"
      Me.lblLast.TextAlign = System.Drawing.ContentAlignment.MiddleRight
      "
      "lblFirst
      "
      Me.lblFirst.Location = New System.Drawing.Point(10, 65)
      Me.lblFirst.Name = "lblFirst"
      Me.lblFirst.Size = New System.Drawing.Size(80, 24)
      Me.lblFirst.TabIndex = 9
      Me.lblFirst.Text = "First Name"
      Me.lblFirst.TextAlign = System.Drawing.ContentAlignment.MiddleRight
      "
      "lblAddress
      "
      Me.lblAddress.Location = New System.Drawing.Point(10, 100)
      Me.lblAddress.Name = "lblAddress"
      Me.lblAddress.Size = New System.Drawing.Size(80, 24)
      Me.lblAddress.TabIndex = 10
      Me.lblAddress.Text = "Address"
      Me.lblAddress.TextAlign = System.Drawing.ContentAlignment.MiddleRight
      "
      "txtAddress
      "
      Me.txtAddress.Location = New System.Drawing.Point(100, 100)
      Me.txtAddress.Name = "txtAddress"
      Me.txtAddress.Size = New System.Drawing.Size(136, 20)
      Me.txtAddress.TabIndex = 2
      Me.txtAddress.Text = ""
      "
      "txtZip
      "
      Me.txtZip.Location = New System.Drawing.Point(100, 205)
      Me.txtZip.Name = "txtZip"
      Me.txtZip.Size = New System.Drawing.Size(136, 20)
      Me.txtZip.TabIndex = 5
      Me.txtZip.Text = ""
      "
      "txtCity
      "
      Me.txtCity.Location = New System.Drawing.Point(100, 135)
      Me.txtCity.Name = "txtCity"
      Me.txtCity.Size = New System.Drawing.Size(136, 20)
      Me.txtCity.TabIndex = 3
      Me.txtCity.Text = ""
      "
      "lblCity
      "
      Me.lblCity.Location = New System.Drawing.Point(10, 135)
      Me.lblCity.Name = "lblCity"
      Me.lblCity.Size = New System.Drawing.Size(80, 24)
      Me.lblCity.TabIndex = 11
      Me.lblCity.Text = "City"
      Me.lblCity.TextAlign = System.Drawing.ContentAlignment.MiddleRight
      "
      "lblState
      "
      Me.lblState.Location = New System.Drawing.Point(10, 170)
      Me.lblState.Name = "lblState"
      Me.lblState.Size = New System.Drawing.Size(80, 24)
      Me.lblState.TabIndex = 12
      Me.lblState.Text = "State"
      Me.lblState.TextAlign = System.Drawing.ContentAlignment.MiddleRight
      "
      "txtPhone
      "
      Me.txtPhone.Location = New System.Drawing.Point(100, 240)
      Me.txtPhone.Name = "txtPhone"
      Me.txtPhone.Size = New System.Drawing.Size(136, 20)
      Me.txtPhone.TabIndex = 6
      Me.txtPhone.Text = ""
      "
      "cmdOK
      "
      Me.cmdOK.Location = New System.Drawing.Point(112, 296)
      Me.cmdOK.Name = "cmdOK"
      Me.cmdOK.TabIndex = 15
      Me.cmdOK.Text = "OK"
      "
      "FrmValid
      "
      Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
      Me.ClientSize = New System.Drawing.Size(312, 341)
      Me.Controls.AddRange(New System.Windows.Forms.Control() {Me.lblPhone, Me.lblZip, Me.lblState, Me.lblCity, Me.lblAddress, Me.lblFirst, Me.lblLast, Me.cmdOK, Me.txtPhone, Me.txtZip, Me.txtState, Me.txtCity, Me.txtAddress, Me.txtFirst, Me.txtLast})
      Me.Name = "FrmValid"
      Me.Text = "Validate"
      Me.ResumeLayout(False)
   End Sub
#End Region
   Private Sub cmdOK_Click(ByVal sender As System.Object, _
      ByVal e As System.EventArgs) Handles cmdOK.Click
      If Not Regex.Match(txtLast.Text, "^[A-Z][a-zA-Z]*$").Success Then
         txtLast.Text = "Invalid Last Name"
         txtLast.Focus()
         Return
      End If
      If Not Regex.Match(txtFirst.Text, "^[A-Z][a-zA-Z]*$").Success Then
         txtFirst.Text = "Invalid First Name"
         txtFirst.Focus()
         Return
      End If
      If Not Regex.Match(txtAddress.Text, "^[0-9]+\s+([a-zA-Z]" & "+|[a-zA-Z]+\s[a-zA-Z]+)$").Success Then
         txtAddress.Text = "Invalid Address"
         txtAddress.Focus()
         Return
      End If
      If Not Regex.Match(txtCity.Text, "^([a-zA-Z]+|[a-zA-Z]" & "+\s[a-zA-Z]+)$").Success Then
         txtCity.Text = "Invalid City"
         txtCity.Focus()
         Return
      End If
      If Not Regex.Match(txtState.Text,"^([a-zA-Z]+|[a-zA-Z]+\s[a-zA-Z]+)$").Success Then
         txtState.Text = "Invalid State"
         txtState.Focus()
         Return
      End If
      If Not Regex.Match(txtZip.Text, "^\d{5}$").Success Then
         txtZip.Text = "Invalid zip code"
         txtZip.Focus()
         Return
      End If
      If Not Regex.Match(txtPhone.Text, "^[1-9]" & "\d{2}-[1-9]\d{2}-\d{4}$").Success Then
         txtPhone.Text = "Invalid Phone Number"
         txtPhone.Focus()
         Return
      End If
      Me.Hide()
      Application.Exit()
   End Sub " cmdOK_Click
End Class