jquery正则表达式验证邮箱

<input type="text" name="email" id="email" onblur="ckemail">
<input type="button" value="check" onClick="ckemail()" />
<div id="ckemaildiv"></div>
<script>
function ckemail(email){
 var reg =/^([a-zA-Z0-9_-])+@([a-zA-Z0-9_-])+((\.[a-zA-Z0-9_-]{2,3}){1,2})$/;
 if(reg.test(email)){
  $("#ckemaildiv").html("*邮箱合法");
 }else{
  $("#ckemaildiv").html("*邮箱不合法");
 }
 }
</script>