How to test for a number...

[konidias]

Ok I'm stumped.. how would it be possible to check what the player says via #c, and check to see if the text is a number?

What I mean is like, if the player says "adosfj", then check if its a number, if it isn't perform an else, but if they say "23502", then it would be correct.

Basically to check if its a number and not letters or other characters.