if (document.images) {       
		var load = false;

		imgTerraOn = new Image(); imgTerraOn.src = "i/index/terra_c.gif";
		imgClearOn = new Image(); imgClearOn.src = "i/index/cb_c.gif";
		imgHDDOn = new Image(); imgHDDOn.src = "i/index/hdd_c.gif";
	
		imgTerraOff = new Image(); imgTerraOff.src = "i/index/terra.gif";
		imgClearOff = new Image(); imgClearOff.src = "i/index/cb.gif";
		imgHDDOff = new Image(); imgHDDOff.src = "i/index/hdd.gif";
	
		load = true;
	}

function imgOn(imgName){
	if (load==1){
		if (document.images){
			srcname = eval(imgName + "On.src");
			if (document[imgName].src != srcname){
				document[imgName].src = srcname;
			}
		}
	}
}
function imgOff(imgName){
	if (load==1){
		if (document.images){
			if (document[imgName].src != eval(imgName + "Off.src")){
				document[imgName].src = eval(imgName + "Off.src");       
			}
		}
	}
}