用javascript 的正则表达式来验证Email地址是否格式正确！

1// 检查 E-mail 是否已被注册
2 function CheckExists()
3 {
4 var e = document.getElementById("mailaddress").value;
5 if(e != "") {
6 if(!/(\S)+[@]{1}(\S)+[.]{1}(\w)+/.test(e))
7 {
8 alert("请输入格式正确的 e-mail 地址！");
9 var email = document.getElementById ( "mailaddress" );
10 email.value = "";
11 email.focus ();
12 }
13 else
14 {
15 QuickRegisterBox.IsEMailExists(e, CheckExists_Callback);
16 }
17 }
18 }