if (document.images)
{
	preload_image_object = new Image();
	// set image url
	image_url = new Array();
	image_url[1] = "../res/button.gif";
	image_url[1] = "../res/button_blue.gif";

	var i = 0;
	for(i=0; i<=1; i++)
	preload_image_object.src = image_url[i];
}