Email validation for Send mail dialog box using jqery

How to add Regular Expression validation for send mail dialog box..i have already set required field validator now i want to validate it using regular expression. It's not working properly at all..need your help..thanks in advance.

$("#submit").click(function (e) {     var email = $("#UserEmail").val();     var emailReg = /^([a-zA-Z0-9_\.\-])+@\[a-zA-Z0-9\-]+\.([a-zA-Z0-9]{3})+$/;     if (!emailReg.test(email)) {         alert("Please Enter Valid Email Id");         e.preventDefault();     } else {         alert("success");     } });

But in the above code i am getting error at @ symbol..