function newImage(arg) {
			if (document.images) {
				rslt = new Image();
				rslt.src = arg;
				return rslt;
			}
		}
		
		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) {
				main8_learn_over = newImage("/images/homepage/main8-learn-over.gif");
				main8_learn_down = newImage("/images/homepage/main8-learn-down.gif");
				main8_download_over = newImage("/images/homepage/main8-download-over.gif");
				main8_download_down = newImage("/images/homepage/main8-download-down.gif");
				preloadFlag = true;
			}
		}

		function toggleVisibility(id, NNtype, IEtype, W3Ctype) {
			if (document.getElementById) {
				eval("document.getElementById(id).style.visibility = \"" + W3Ctype + "\"");
				} else {
					if (document.layers) {
					document.layers[id].visibility = NNtype;
					} else {
						if (document.all) {
						eval("document.all." + id + ".style.visibility = \"" + IEtype + "\"");
					}
				}
			}
		}