Do you mean "if the variable contains '@' in it"?
If that's the case, check the string sub category of the php manual.
Oh, er, are you trying to check to see that the email address is valid? Look in the shared code lib. The link should be on your left near the top. There are email validation functions to be had there. If you can find any, you could allways use something like strstr().
Late on,
Terrence
