<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title></title>
</head>
<body>
<p>
输入验证码：<input type="text" name="" id="inputCode" value="" placeholder="请输入输入验证码"/>
<span id="tyzm"></span>
</p>
<p>
<input type="button" name="" id="checkCode" value="获取验证码"onclick="createCode(4); " />
</p>
<p>
<input type="button" name="" id="" value="确定"onclick="validateCode()" />
</p>
<script type="text/javascript">
//页面加载时，生成随机验证码
window.onload=function(){
createCode(4);
}
//生成验证码的方法
function createCode(length) {
var code = "";
var codeLength = parseInt(length); //验证码的长度
var checkCode = document.getElementById("checkCode");
var checkCode = document.getElementById("inputCode");
////所有候选组成验证码的字符，当然也可以用中文的
var codeChars = 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',
'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');
//循环组成验证码的字符串
for (var i = 0; i < codeLength; i++)
{
//获取随机验证码下标
var charNum = Math.floor(Math.random() * 62);
//组合成指定字符验证码
code += codeChars[charNum];
}
if (checkCode)
{
//为验证码区域添加样式名
checkCode.className = "code";
//将生成验证码赋值到显示区
tyzm.innerHTML = code;
}
}
//检查验证码是否正确
function validateCode()
{
//获取显示区生成的验证码
var tyzm = document.getElementById("tyzm").innerHTML;
//获取输入的验证码
var inputCode = document.getElementById("inputCode").value;
//console.log(checkCode);
//console.log(inputCode);
if (inputCode.length <= 0)
{
alert("请输入验证码！");
}
else if (inputCode.toUpperCase() != tyzm.toUpperCase())
{
alert("验证码输入有误！");
createCode(4);
}
else
{
alert("验证码正确！");
}
}
</script>
</body>
</html>