function roll(img_name, img_src)
			{
			   document[img_name].src = img_src;
			}

		
		function layerSetup(id,visibility)
			{
				if(document.getElementById)
				{
					this.obj = document.getElementById(id).style;
					this.obj.visibility = visibility;
					return this.obj;
				}
				else if(document.all)
				{
					this.obj = document.all[id].style;
					this.obj.visibility = visibility;
					return this.obj;
				}
				else if(document.layers)
				{
					this.obj = document.layers[id];
					this.obj.visibility = visibility;
					return this.obj;
				}
			}

		function visVisible(param)
			{
				new layerSetup(param,'visible');
			}

		function visHidden(param)
			{
				new layerSetup(param,'hidden');
			}