function newImage(arg) {
	if (document.images) {
		rslt = new Image();
		rslt.src = arg;
		return rslt;
	}
}

function changeImages() {
	if (document.images && (preloadFlag == true)) {
		for (var i=0; i<changeImages.arguments.length; i+=2) {
			document[changeImages.arguments[i]].src = changeImages.arguments[i+1];
		}
	}
}

var preloadFlag = false;
function preloadImages() {
	if (document.images) {
		header2_03_over = newImage("slice_images/header2_03-over.jpg");
		header2_05_over = newImage("slice_images/header2_05-over.jpg");
		header2_08_over = newImage("slice_images/header2_08-over.jpg");
		header2_09_over = newImage("slice_images/header2_09-over.jpg");
		header2_10_over = newImage("slice_images/header2_10-over.jpg");
		header2_11_over = newImage("slice_images/header2_11-over.jpg");
		header2_12_over = newImage("slice_images/header2_12-over.jpg");
		header2_14_over = newImage("slice_images/header2_14-over.jpg");
		header2_15_over = newImage("slice_images/header2_15-over.jpg");
		footer2_02_over = newImage("slice_images/footer2_02-over.jpg");
		footer2_03_over = newImage("slice_images/footer2_03-over.jpg");
		footer2_04_over = newImage("slice_images/footer2_04-over.jpg");
		footer2_05_over = newImage("slice_images/footer2_05-over.jpg");
		footer2_06_over = newImage("slice_images/footer2_06-over.jpg");
		footer2_07_over = newImage("slice_images/footer2_07-over.jpg");
		footer2_08_over = newImage("slice_images/footer2_08-over.jpg");
		footer2_09_over = newImage("slice_images/footer2_09-over.jpg");
		footer2_10_over = newImage("slice_images/footer2_10-over.jpg");
		preloadFlag = true;
	}
}

function hide_box(boxID) {
	document.getElementById(boxID).style.display = "none";
}

function show_box(boxID) {
	document.getElementById(boxID).style.display = "";
}

var current_selected_category = 0;

function category_change() {
	var x = document.getElementById("sel_category_id").value;
	
	if(current_selected_category > 0) {
		hide_box("category_"+current_selected_category);
	}
	
	if(current_selected_category == -1) {
		hide_box("all_box");
	}
	
	if(x == -1) {
		show_box("all_box");
	} else {
		show_box("category_"+x);
	}
	current_selected_category = x;
}