【www.gdgbn.com--正则表达式】

<script language="jscript">
function check(object)
          {
        var s =document.getelementbyid(object).value;
             var pattern =/^[a-za-z0-9_-]{1,}@[a-za-z0-9_-]{1,}.[a-za-z0-9_-.]{1,}$/;
                 if(s!="")
                 {
                     if(!pattern.exec(s))
                     {
                      alert("请输入正确的邮箱地址");
                      object.value="";
                      object.focus();
                     }
                 }
               
        }
  
function ismail(mail) {
 var filter  = /^([a-za-z0-9_.-])+@(([a-za-z0-9-])+.)+([a-za-z0-9]{2,4})+$/;
 if (filter.test(mail)) return true;
 else {
 alert("您的电子邮件格式不正确");
 return false;}
}

</script>

本文来源：http://www.gdgbn.com/aspjiaocheng/27369/