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

var preloadFlag = false;
function preloadImages(img) {
	if (document.images) {
		pre_bt_payer_roll = newImage(img);
		preloadFlag = true;
	}
}

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