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) {
		// over images
		home_over = newImage("images/home-over.gif");
		web_design_over = newImage("images/web_design-over.gif");
		web_programming_over = newImage("images/web_programming-over.gif");
		database_design_over = newImage("images/database_design-over.gif");
		photography_over = newImage("images/photography-over.gif");
		marketing_over = newImage("images/marketing-over.gif");
		interactive_over = newImage("images/interactive-over.gif");
		graphic_design_over = newImage("images/graphic_design-over.gif");
		contcat_info_over = newImage("images/contcat_info-over.gif");
		personal_over = newImage("images/personal-over.gif");
		// down images
		home_down = newImage("images/home-down.gif");
		web_design_down = newImage("images/web_design-down.gif");
		web_programming_down = newImage("images/web_programming-down.gif");
		database_design_down = newImage("images/database_design-down.gif");
		photography_down = newImage("images/photography-down.gif");
		marketing_down = newImage("images/marketing-down.gif");
		interactive_down = newImage("images/interactive-down.gif");
		graphic_design_down = newImage("images/graphic_design-down.gif");
		contcat_info_down = newImage("images/contcat_info-down.gif");
		personal_down = newImage("images/personal-down.gif");
		preloadFlag = true;
	}
}