if (document.images) {
	var preload_image = new Array();
	var imgPath = new Array();	
	imgPath[0] = "demo-btn-on.gif";
	imgPath[1] = "demo-btn-off.gif";
	
	var imgLength = imgPath.length;
	var img = "images/";
	var i = 0;
	
	for(i = 0; i < imgLength; i++) {
		preload_image[i] = new Image();
		preload_image[i].src = img + imgPath[i];
	}
}