Want Help "How can i use numeric key instead of alphabetic in text box "

[yousafc#]

i have calculator project when i insert numeric key i work properly.But when i insert
a,b,c,d, etc. it give me error and application stop.send me code how can i stop writing
alphabetic key in text box.only use numeric

[ddanbe]

If you look in the C# code snippet section, you can find this snippet: http://www.daniweb.com/code/snippet217265.html
Same code I used in the zip file of a previous thread I sent you.
Success.