elseif(!eregi("^[_a-z0-9-]+(\.[_a-z0-9-]+)*@[a-z0-9-]+(\.[a-z0-9-]+)*(\.[a-z]{2,3})$", $user_email)) 
Even i tried with preg_match in this too i am getting 
Warning:
preg_match() [function.preg-match]: No ending delimiter '^' found in C:\wamp\www\Saravanan\jQuery\jQuery - Samples\sign_and_login_using_jquery_ajax_and_php\sign_and_login_using_jquery_ajax_and_php\vpb_save_details.php on line 29
Call Stack
 
     
     
    