前台是个什么东西-JavaScript-一个验证码的小程序

前台是个什么东西-JavaScript-一个验证码的小程序 前台是个什么东西---JavaScript---一个验证码的小程序 !DOCTYPE html PUBLIC -//W3C//DTD XHTML 1.0 Transitional//EN html xmlns= head title 无标页 /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 //在全局 定义验证码 var code function createCode{ code = //验证码的长度 var codeLength = 6 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=0i codeLengthi++){ var charIndex = Math.floor(Math.random*36) code +=selectChar[charIndex] } if(checkCode){ checkCode.className= code checkCode.value = code } } function validate { var inputCode = document.getElementById( input1 ).value if(inputCode.length =0){ alert( 请输入验证码～ ) }else if(inputCode != code ){ alert( 验证码输入错误～ ) createCode//刷新验证码 }else{ alert( ^-^ OK ) } } /script /head body onload= createCode form action= # input type= text id= input1 / input type= text onclick= createCode readonly= readonly id= checkCode class= unchanged style= width: 80px / br / input id= Button1 onclick= validate type= button value= 确定 / /form /body /html