check for invalide characters in the URL

[tbobker]

Im not sure how to do this. I want to make sure that no one enters invalide characters into the URL - sql injection. How can i make sure that the characters after the URL only contain digits and if anything else is found display an error page as necessary?

[devinemke]

are you just checking a specific GET variable? if so then run it thru [man]is_numeric[/man].

[laserlight]

If you literally means "contain contain digits", then [man]ctype_digit[/man] may be what you want.