正则验证
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title></title>
</head>
<body>
<script type="text/javascript">
window.onload=function(){
var check=document.getElementById("btn").onclick=function(){
var email=document.getElementById("email").value;//获取输入的字符串
var emailRegExp=/^\w+([-+.]\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*$/;//验证邮箱的正则表达式
var ok=emailRegExp.test(email);//验证是否符合要求
if(ok){
document.getElementById("erroremail").innerText="输入的格式符合要求";
}else{
document.getElementById("erroremail").innerText="输入的格式不符合要求！！！";
}
}
document.getElementById("email").onfocus=function(){
document.getElementById("erroremail").innerText="";
}
}
</script>
<input type="text" id="email" />
<span id="erroremail" style=" font: 12px; color: red;"></span>
<br />
<input type="button" value="验证邮箱" id="btn" />
</body>
</html>
