js-验证码

//验证码
var code;
//testCode是验证码字符块,此事件加在’换一换‘链接以及body的onload上
util.createCode = function(testCode,len) {
code = "";
var codeLength = len; //验证码的长度
var checkCode = document.getElementById(testCode);
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‘); //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 charNum = Math.floor(Math.random() * 52);
code += codeChars[charNum];
}
if (checkCode) {
checkCode.innerHTML = code;
}
}
//iptId是验证码的输入框,此事件加在’注册‘或‘提交’按钮上
util.validateCode = function(iptId) {
var inputCode = document.getElementById(iptId).value;
var input = document.getElementById(iptId);
if (inputCode.length <= 0) {
alert("请输入验证码！");
} else if (inputCode.toUpperCase() != code.toUpperCase()) {
alert("验证码输入有误！");
createCode();
} else {
input.style.border = "2px solid rgb(153,204,51)";
}
}

js-验证码

原文：http://www.cnblogs.com/weimo10235/p/6493122.html