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) {
	    home = newImage("../Assets/Images/menu/home.gif");
		home_over = newImage("../Assets/Images/menu/home_over.gif");
		home_down = newImage("../Assets/Images/menu/home_down.gif");
	    button = newImage("../Assets/Images/menu/button.gif");		
		intro = newImage("../Assets/Images/menu/Introdu.gif");
		intro_over = newImage("../Assets/Images/menu/Introdu_over.gif");
		intro_down = newImage("../Assets/Images/menu/Introdu_down.gif");
		interact = newImage("../Assets/Images/menu/Interactive.gif");
		interact_over = newImage("../Assets/Images/menu/Interactive_over.gif");
		interact_down = newImage("../Assets/Images/menu/Interactive_down.gif");
		more = newImage("../Assets/Images/menu/AndMore.gif");
		more_over = newImage("../Assets/Images/menu/AndMore_over.gif");
		more_down = newImage("../Assets/Images/menu/AndMore_down.gif");				
		color = newImage("../Assets/Images/menu/Color_perception.gif");
		color_over = newImage("../Assets/Images/menu/Color_perception_over.gif");
		color_down = newImage("../Assets/Images/menu/Color_perception_down.gif");
		light = newImage("../Assets/Images/menu/Light.gif");
		light_over = newImage("../Assets/Images/menu/Light_over.gif");
		light_down = newImage("../Assets/Images/menu/Light_down.gif");		
		EMR = newImage("../Assets/Images/menu/EMR.gif");
		EMR_over = newImage("../Assets/Images/menu/EMR_over.gif");
		EMR_down= newImage("../Assets/Images/menu/EMR_down.gif");
		bbody = newImage("../Assets/Images/menu/Black_bodies.gif");
		bbody_over = newImage("../Assets/Images/menu/Black_bodies_over.gif");
		bbody_down = newImage("../Assets/Images/menu/Black_bodies_down.gif");		
		Spectroscopy = newImage("../Assets/Images/menu/Spectroscopy.gif");
		Spectroscopy_over = newImage("../Assets/Images/menu/Spectroscopy_over.gif");
		Spectroscopy_down = newImage("../Assets/Images/menu/Spectroscopy_down.gif");		
		Doppler = newImage("../Assets/Images/menu/Doppler.gif");
		Doppler_over = newImage("../Assets/Images/menu/Doppler_over.gif");
		Doppler_down = newImage("../Assets/Images/menu/Doppler_down.gif");
		sun = newImage("../Assets/Images/menu/Sun.gif");
		sun_over = newImage("../Assets/Images/menu/Sun_over.gif");
		sun_down = newImage("../Assets/Images/menu/Sun_down.gif");	
		exsun = newImage("../Assets/Images/menu/ExSun.gif");
		exsun = newImage("../Assets/Images/menu/ExSun_over.gif");
		exsun = newImage("../Assets/Images/menu/ExSun_down.gif");
		nova = newImage("../Assets/Images/menu/DwarfNova.gif");
		nova = newImage("../Assets/Images/menu/DwarfNova_over.gif");
		nova = newImage("../Assets/Images/menu/DwarfNova_down.gif");				
	    button = newImage("../Assets/Images/b.gif");
		button_over = newImage("../Assets/Images/b_over.gif");
		button_down = newImage("../Assets/Images/b_down.gif");
		preloadFlag = true;
	}

}