function showHideLayer(layerId)
			{
				var i=0;
				var layerCount=8;
				for(i=1;i<=layerCount;i++)
				{
					LAYER=eval("window.layer"+i+".style")
					if (i!=layerId)
						LAYER.display='none';
					else
						LAYER.display='';	
						
				}
			}