var imageDir = "images/";
	
	 // preload navbar images
	 home_on = new Image();
	 home_on.src = imageDir + "home_on.gif";
	 home_off = new Image();
	 home_off.src = imageDir + "home_off.gif";
	  
	 bracfacts_on = new Image();
	 bracfacts_on.src = imageDir + "bracfacts_on.gif";
	 bracfacts_off = new Image();
	 bracfacts_off.src = imageDir + "bracfacts_off.gif";
	  
	 about_apg_on = new Image();
	 about_apg_on.src = imageDir + "about_apg_on.gif";
	 about_apg_off = new Image();
	 about_apg_off.src = imageDir + "about_apg_off.gif";
	  
	 apg_tech_centr_on = new Image();
	 apg_tech_centr_on.src = imageDir + "apg_tech_centr_on.gif";
	 apg_tech_centr_off = new Image();
	 apg_tech_centr_off.src = imageDir + "apg_tech_centr_off.gif";
	  
	 about_army_allnc_on = new Image();
	 about_army_allnc_on.src = imageDir + "about_army_allnc_on.gif";
	 about_army_allnc_off = new Image();
	 about_army_allnc_off.src = imageDir + "about_army_allnc_off.gif";
	 
	 links_on = new Image();
	 links_on.src = imageDir + "links_on.gif";
	 links_off = new Image();
	 links_off.src = imageDir + "links_off.gif";
	 
	 sponsor_on = new Image();
	 sponsor_on.src = imageDir + "sponsor_on.gif";
	 sponsor_off = new Image();
	 sponsor_off.src = imageDir + "sponsor_off.gif";
	 
	 director_enter_on = new Image();
	 director_enter_on.src = imageDir + "director_enter_on.gif";
	 director_enter_off = new Image();
	 director_enter_off.src = imageDir + "director_enter_off.gif";
	 
	 function topMenuSwap(image, state) {
		var thisImage = document.getElementById(image);
		thisImage.src = eval(image + "_" + state + ".src");
		return;
	 }