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    }