function newImage(arg) {
  if (document.images) {
    rslt = new Image();
    rslt.src = arg;
    return rslt;
  }
}


function changeImage(obj,fn) {if (document.images && (preloadFlag == true)) {obj.src = fn}}

function changeImages() {
  if (document.images && (preloadFlag == true)) {
    for (var i=0; i<changeImages.arguments.length; i+=2) {
      document[changeImages.arguments[i]].src = changeImages.arguments[i+1];
    }
  }
}

var preloadFlag = false;

function preloadImages(){
 if (document.images) {
    preloadFlag = true;
 prl0 = newImage('images/arrow_blue.gif');

prl10 = newImage('images/b_brands_o.gif');
prl11 = newImage('images/b_agencies_o.gif');
prl12 = newImage('images/b_networks_o.gif');
prl13 = newImage('images/b_publishers_o.gif');


 }


 }


function change_bgImage(id,fn)
    {
        document.getElementById(id).style.backgroundImage = "url(images/"+fn+")";
    }