PHP isEmail Function

Code to validate email in PHP using Preg Match.

This will cover emails of format:

asdfasdf@asdfasdf.com

function isEmail($email)

{

      if(preg_match("~([a-zA-Z0-9!#$%&'*+-/=?^_`{|}~])@([a-zA-Z0-9-]).([a-zA-Z0-9]{2,4})~",$email)) 

        return true;

   else

        return false;

}