纯前端实现验登录证码

js验证码

.code

{

background:url(code_bg.jpg);

font-family:Arial;

font-style:italic;

color:blue;

font-size:30px;

border:0;

padding:2px 3px;

letter-spacing:3px;

font-weight:bolder;

float:left;

cursor:pointer;

width:150px;

height:60px;

line-height:60px;

text-align:center;

vertical-align:middle;

}

a

{

text-decoration:none;

font-size:12px;

color:#288bc4;

}

a:hover

{

text-decoration:underline;

}

var code;

function createCode()

{

code = "";

var codeLength = 6; //验证码的长度

var checkCode = document.getElementById("checkCode");

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.className = "code";

checkCode.innerHTML = code;

}

}

function validateCode()

{

var inputCode=document.getElementById("inputCode").value;

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

{

alert("验证码正确！");

}

}

看不清换一张

验证码：

请输入验证码