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;	
}