var	preloadFlag = false;

function loadImage(name, src) {
  eval(name + " = new Image();");
  eval(name + '.src = "'+src+'";');
}

function changeImage(dpic, pic) {
  if (document.images && (preloadFlag == true))
    eval("document.images['"+dpic+"'].src="+pic+".src;");
}

function enable(what) {
  changeImage(what, what+'_');
}

function disable(what) {
  changeImage(what, what);
}	

function loadAll(){
	// group 1
	loadImage("home", "Images/menu/menu_home.gif");
	loadImage("home_", "Images/menu/menu_home_.gif");
	loadImage("directory", "Images/menu/menu_osddir.gif");
	loadImage("directory_", "Images/menu/menu_osddir_.gif");
	loadImage("find", "Images/menu/menu_find.gif");
	loadImage("find_", "Images/menu/menu_find_.gif");
	loadImage("learning", "Images/menu/menu_learning.gif");
	loadImage("learning_", "Images/menu/menu_learning_.gif");
	loadImage("resources", "Images/menu/menu_resource.gif");
	loadImage("resources_", "Images/menu/menu_resource_.gif");
	// group 2
	loadImage("about", "Images/menu/menu_about.gif");
	loadImage("about_", "Images/menu/menu_about_.gif");
	loadImage("aboutservice", "Images/menu/menu_aboutservice.gif");
	loadImage("aboutservice_", "Images/menu/menu_aboutservice_.gif");
	loadImage("aboutresource", "Images/menu/menu_aboutresource.gif");
	loadImage("aboutresource_", "Images/menu/menu_aboutresource_.gif");
	loadImage("faq", "Images/menu/menu_faq.gif");
	loadImage("faq_", "Images/menu/menu_faq_.gif");
	loadImage("contactus", "Images/menu/menu_contactus.gif");
	loadImage("contactus_", "Images/menu/menu_contactus_.gif");
	
	preloadFlag = true;	
}