[php] email validation function

// http://scriptdemo.blogspot.ca // a simple way to check whether an email address is valid function CheckEmail($str) {    $str=str_replace('#','@',$str);    if (preg_match("/^[a-zA-Z]+([\._][a-zA-Z0-9]+)*@([a-zA-Z0-9]+\.)+[a-zA-Z]{2,4}$/",$str))     {       return TRUE;     }    else     {       return FALSE;     } }

people prefer something from php itself might be interested in filter_var