javascript验证码生成代码推荐学习

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> 
<html xmlns="http://www.w3.org/1999/xhtml" > 
<head> 
<title>javascript 验证码实现代码_脚本之家测试</title> 
<style type="text/css"> 
.code 
{}{ 
background-image:url(code.jpg); 
font-family:Arial; 
font-style:italic; 
color:Red; 
border:0; 
padding:2px 3px; 
letter-spacing:3px; 
font-weight:bolder; 
} 
.unchanged 
{}{ 
border:0; 
} 
</style> 
<script language="javascript" type="text/javascript">

var code ; //在全局 定义验证码 
function createCode() 
{ 
code = ""; 
var codeLength = 6;//验证码的长度 
var checkCode = document.getElementById("checkCode"); 
var selectChar = new Array(0,1,2,3,4,5,6,7,8,9,'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z');//所有候选组成验证码的字符，当然也可以用中文的

for(var i=0;i<codeLength;i++) 
{

var charIndex = Math.floor(Math.random()*36); 
code +=selectChar[charIndex];

} 
if(checkCode) 
{ 
checkCode.className="code"; 
checkCode.value = code; 
}

}

}

</ script> 
</head> 
<body onload="createCode()"> 
 
</body> 
</html>

[Ctrl+A 全选注:如需引入外部Js需刷新才能执行]

javascript验证码生成代码推荐学习_javascript技巧