<!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
check()
{
var
obj=document.getElementById("email")
if(obj.value!="")
{
var
str=obj.value;
if(str.indexOf("@")!=-1)
{
if(str.indexOf(".")!=-1){
var
a=str.split("@");
if
(a[0].length>1)
{
document.getElementById("mess").innerHTML="<font
color=‘blue‘>正确</font>";
}else
{document.getElementById("mess").innerHTML="<font
color=‘red‘>长度错误</font>";}
}else
{document.getElementById("mess").innerHTML="<font
color=‘red‘>错误</font>";}
}else{
document.getElementById("mess").innerHTML="<font
color=‘red‘>错误</font>";
}
}else{document.getElementById("mess").innerHTML="<font
color=‘blue‘>邮箱是空的</font>";}
}
</script>
</head>
<body>
<lable>email:</lable><input type="text"
id="email"/>
<input type="button" value="验证"
onclick="check()">
<br/><span
id="mess"></span>
</body>
</html>
email:
正确
email:
长度错误
email:
错误
原文：http://www.cnblogs.com/lowbrid/p/3554087.html