Binaryworld - ForceTextBoxNumeric - Create a numeric Textbox ... [ VB -> Forms & Controls ]

Private Declare Function GetWindowLong Lib "user32" Alias "GetWindowLongA" _
  (ByVal hWnd As Long, ByVal nIndex As Long) As Long
Private Declare Function SetWindowLong Lib "user32" Alias "SetWindowLongA" _
  (ByVal hWnd As Long, ByVal nIndex As Long, ByVal dwNewLong As Long) As Long

' Force a TextBox control to accept only numeric digits
' Cancel the effect by passing Force = False
'
' Note that it only accepts positive integer values

Sub ForceTextBoxNumeric(TextBox As TextBox, Optional Force As Boolean = True)
  Dim style As Long
  Const GWL_STYLE = (-16)
  Const ES_NUMBER = &H2000

  ' get current style
  style = GetWindowLong(TextBox.hWnd, GWL_STYLE)
  If Force Then
    style = style Or ES_NUMBER
  Else
    style = style And Not ES_NUMBER
  End If
  ' enforce new style
  SetWindowLong TextBox.hWnd, GWL_STYLE, style
End Sub