decimal and backspace

If Not IsNumeric(Chr(KeyAscii)) Then KeyAscii = 13

I am using the above and need to add backspace and decimal to the allowed characters. I'm at work and don'thave msdn to look it up...

Help please...code...chr(ascii) what?

text box called text1....

Private Sub Text1_KeyPress(KeyAscii As Integer)
If KeyAscii = 8 Then Exit Sub ' backspace

If KeyAscii = 46 Then
If InStr(1, Text1.Text, ",") <> 0 Then ' only allow one decimal
KeyAscii = 0
Else
Exit Sub ' decimal
End If
End If

If Not IsNumeric(Chr(KeyAscii)) Then KeyAscii = 0
End Sub

Thanks,
Wayne