E-mail Validation

[Banksy]

I need to know how to determine that this entered e-mail address (MissProgrammer@hotmail.com is correct and
this e-mail address (MissProgrammerhotmailcom) is incorrect!
I belive that I have to use String Comparsion. Any suggestions?

[pyro]

Our resident regular expression expert, Jeff Mott, has provided a very comprehensive email validation regexp: http://forums.webdeveloper.com/showthread.php?s=&threadid=9604#post49397