JAvascript生成検証コード

function validteCode()//     
{
   
    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','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');     //         
    var colors = new Array("Red","Green","Blue","Maroon","Aqua","Fuchsia","Lime","Olive","Silver");
    for(var i=0;i < codes.length;i++)
    {//       
        codes[i] = selectChar[Math.floor(Math.random()*62)]; 
    }
    //var spans = document.getElementById("divCode").all;
    
    for(var i=0;i<4;i++)
    {
        document.getElementById(i+1).innerHTML="<font size=6>"+codes[i]+"</font>";
        document.getElementById(i+1).style.color = colors[Math.floor(Math.random()*10)];    //         
        
    }
}


<div id="ma">
         <span id="1"></span><span id="2"></span><span id="3"></span><span id="4" ></span>
         </div>