var activePage = "welkom";

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

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

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

var preloadFlag = true;
function preloadImages() {
	if (document.images) {
		Imgsales = newImage("images/sales_n.jpg.gif");
		Imgsales = newImage("images/sales_h.jpg.gif");
		Imgrental = newImage("images/rental_n.jpg.gif");
		Imgrental = newImage("images/rental_h.jpg.gif");
		preloadFlag = true;
	}
}

function setActivePageFrame(name) { 
	if (document.images) { 
        	changeImagesFrame(name, eval("'menu_" + activePage + "'"), eval("'images/Buttons/" + activePage + ".gif'"));
        	changeImagesFrame(name, eval("'menu_" + name + "'"), eval("'images/Buttons/" + name + "Roll.gif'"));
        	parent.buttons.activePage = name;
	} 
}

function setActivePage(name) { 
	if (document.images) { 
        	changeImages(name, eval("'menu_" + activePage + "'"), eval("'images/Buttons/" + activePage + ".gif'"));
        	changeImages(name, eval("'menu_" + name + "'"), eval("'images/Buttons/" + name + "Roll.gif'"));
        	activePage = name;
	} 
}