if (document.images) {
	sampleoff = new Image (0,0);
	etouroff = new Image (0,0);
	demooff = new Image (0,0);
	
	sampleon = new Image (0,0);
	etouron = new Image (0,0);
	demoon = new Image (0,0);

	sampleoff.src = "images/sample_off.jpg";
	etouroff.src = "images/etour_off.jpg";
	demooff.src = "images/demo_off.jpg";

	sampleon.src = "images/sample_on.jpg";
	etouron.src = "images/etour_on.jpg";
	demoon.src = "images/demo_on.jpg";
	
}

function act(imgName) {

	if (document.images) {
		document[imgName].src = eval(imgName + 'on.src');
	}
   
}

function inact(imgName) {

	if (document.images) {
		document[imgName].src = eval(imgName + 'off.src');
	}
   
}