javascript-利用正则表达式检查电子邮件格式

//Check Email Format
function CheckEmail(theform)
{
email=theform.rs_email.value;
if(email=="")
{
alert("邮箱地址不能为空！");
theform.rs_email.focus();
return false;
}
else
{
var re = /^[\w.-]+@([0-9a-z][\w-]+\.)+[a-z]{2,3}$/i;

if(re.test(email))
{
return true;
}
else
{
alert("邮箱地址格式不正确！");
theform.rs_email.focus();
return false;
}
}
}