Hi all,
C# newbie after migrating from VB. I wish to have only valid numbers
entered into a txtbox . i.e only one decimal point.

///////////////////My VB code for this is:
Private Sub txtGcost_KeyPress(KeyAscii As Integer)
   Select Case KeyAscii
   Case 48 To 57, 8
    Case 46
    If InStr(txtGcost.Text, ".") > 0 Then
       'Decimal point already there.
       KeyAscii = 0
        If Left(txtGcost.Text, 1) = "." Then
         txtGcost = "0."
       End If
   End If
   Case Else
   KeyAscii = 0
 End Select
End Sub

///////////////My C# code is:

private void txtCost_KeyPress(object sender, KeyPressEventArgs e)
       {
           {
               const char Delete = (char)8;
               const char dot = (char)46;
               string check4dot = ".";
               string searchstring = txtCost.Text;
               int checkit = searchstring.IndexOf(check4dot);

               if (checkit >1 )

                   {

                   e.Handled = !Char.IsDigit(e.KeyChar) && e.KeyChar
!= Delete && e.KeyChar != dot;

Which works fine, except for not allowing no more than one decimal
point,

Thank in advance