function $findFirstTag(obj,tagname){for(var i=0;i<obj.childNodes.length;i++){if(obj.childNodes[i].tagName==tagname){return obj.childNodes[i]}}}
function UrlSwitch(image){
   filename=image.src.substring(image.src.lastIndexOf('/')+1,image.src.lastIndexOf('.'))
   exp=image.src.substring(image.src.lastIndexOf('.'));
   
   if(filename.indexOf("_over") < 0)
       filename=filename.substring(0,filename.lastIndexOf('_'))+"_over"+exp;
   else
       filename=filename.substring(0,filename.lastIndexOf('_'))+"_up"+exp;
       
   image.src=image.src.substring(0,image.src.lastIndexOf('/')+1)+filename;
}

function Preload(images){
    for(var k in images){
        images[k]=new Image();
        images[k].src=k;
    }
}