var ImageStack = new Object();


ImageStack.makeStack = function( name, element1, element2, element3, element4, element5, element6, element7) {
	if ( !ImageStack.elements) {
		ImageStack.elements = new Object;
	}
	
	ImageStack.elements[name] = new Array( element1, element2, element3, element4, element5, element6, element7);
}

ImageStack.mouseover = function( element, hoverImage) {
	var image = document.getElementById( element);
	if ( !image.getAttribute( "preonsrc")) {
		image.setAttribute( "prehighlightsrc", image.src);
		image.src = hoverImage;
	}
}

ImageStack.mouseout = function( element) {
	var image = document.getElementById( element);
	if ( !image.getAttribute( "preonsrc")  &&  image.getAttribute( "preHighlightSrc")) {
		image.src = image.getAttribute( "prehighlightsrc");
		image.removeAttribute( "prehighlightsrc");
	}
}

ImageStack.activate = function( name, elementToActivate, activeImage) {
	var imagestack = ImageStack.elements[name];
	
	if ( !imagestack) {
		return;
	}

	// reset all elements
	for ( var i = 0; i < imagestack.length; i++) {
		var element = imagestack[i];
		if ( !element) {
			continue;
		}
		var image = document.getElementById( element);

		if ( image.getAttribute( "preonsrc")) {
			image.src = image.getAttribute( "preonsrc");
			image.removeAttribute( "preonsrc");
		}
		else if ( image.getAttribute( "preHighlightSrc")) {
			image.src = image.getAttribute( "prehighlightsrc");
			image.removeAttribute( "prehighlightsrc");
		}
	}

	// show element
	var imageToActivate = document.getElementById( elementToActivate);
	imageToActivate.setAttribute( "preonsrc", imageToActivate.src);
	imageToActivate.src = activeImage;
}