<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html>
<head>
<script type="text/javascript" >
function chkEmail(){
var email=document.getElementById('email').value;
var obj=document.getElementById('showMess');
var pattern=/^[a-zA-Z]\w+[@]\w+[.][\w.]+$/;
if(pattern.test(email)){
obj.innerText="正确";
obj.style.color='green';
}else{
obj.innerText="错误";
obj.style.color='red';
}
}
</script>
</head>
<body>
<lable>电子邮件:</lable><input type="text" id="email" onblur="chkEmail()"/>
<span id="showMess"> </span>
</body>
</html>