var code ;window.onload=function createCode(){ code = "";var codeLength = 4;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');
for(var i=0;i<codeLength;i++){var charIndex = Math.floor(Math.random()*36);code +=selectChar[charIndex];}if(checkCode){checkCode.className="code";checkCode.innerHTML = code;}}