var pre_images = new Array();

function preLoadImage(id, src) {
	pre_images[id] = new Image();
	pre_images[id].src = src;
}

initImages = function doInitImages() {
	pre_load_images();
}

function pre_load_images() {
	
	/** top menu */
	preLoadImage('line_portal', '/public/site/images/design/top/line_portal.jpg');	
	preLoadImage('line_contact', '/public/site/images/design/top/line_contact.jpg');	
	preLoadImage('line_downloads', '/public/site/images/design/top/line_downloads.jpg');	
	preLoadImage('line_links', '/public/site/images/design/top/line_links.jpg');		
	
	preLoadImage('img_portal', '/public/site/images/design/top/menu_portal.jpg');		
	preLoadImage('img_portal_over', '/public/site/images/design/top/menu_portal_over.jpg');
	
	preLoadImage('img_contact', '/public/site/images/design/top/menu_contact.jpg');		
	preLoadImage('img_contact_over', '/public/site/images/design/top/menu_contact_over.jpg');
	
	preLoadImage('img_downloads', '/public/site/images/design/top/menu_downloads.jpg');		
	preLoadImage('img_downloads_over', '/public/site/images/design/top/menu_downloads_over.jpg');
	
	preLoadImage('img_links', '/public/site/images/design/top/menu_links.jpg');		
	preLoadImage('img_links_over', '/public/site/images/design/top/menu_links_over.jpg');	
	
	/** menu items */
	preLoadImage('img_nil', '/public/site/images/design/menu/menu_nil.gif');		
	preLoadImage('img_nil_over', '/public/site/images/design/menu/menu_nil_over.gif');	
	
	preLoadImage('img_onderwijs', '/public/site/images/design/menu/menu_onderwijs.gif');		
	preLoadImage('img_onderwijs_over', '/public/site/images/design/menu/menu_onderwijs_over.gif');		
	
	preLoadImage('img_informatie', '/public/site/images/design/menu/menu_informatie.gif');		
	preLoadImage('img_informatie_over', '/public/site/images/design/menu/menu_informatie_over.gif');
	
	preLoadImage('img_certificatie', '/public/site/images/design/menu/menu_certificatie.gif');		
	preLoadImage('img_certificatie_over', '/public/site/images/design/menu/menu_certificatie_over.gif');	

	preLoadImage('img_webshop', '/public/site/images/design/menu/menu_webshop.gif');		
	preLoadImage('img_webshop_over', '/public/site/images/design/menu/menu_webshop_over.gif');	
	
	preLoadImage('img_agenda', '/public/site/images/design/menu/menu_agenda.gif');		
	preLoadImage('img_agenda_over', '/public/site/images/design/menu/menu_agenda_over.gif');	
	
	/** menu bg's */
	preLoadImage('bg_andere', '/public/site/images/design/menu/bg_andere.jpg');	
	preLoadImage('bg_cert', '/public/site/images/design/menu/bg_cert.jpg');	
	preLoadImage('bg_erkenning', '/public/site/images/design/menu/bg_erkenning.jpg');	
	preLoadImage('bg_informatie', '/public/site/images/design/menu/bg_informatie.jpg');
	preLoadImage('bg_kader', '/public/site/images/design/menu/bg_kader.jpg');
	preLoadImage('bg_lasgroep', '/public/site/images/design/menu/bg_lasgroep.jpg');
	preLoadImage('bg_les', '/public/site/images/design/menu/bg_les.jpg');
	preLoadImage('bg_onderwijs', '/public/site/images/design/menu/bg_onderwijs.jpg');
	preLoadImage('bg_opleidingen', '/public/site/images/design/menu/bg_opleidingen.jpg');	
	preLoadImage('bg_vak', '/public/site/images/design/menu/bg_vak.jpg');	
	preLoadImage('bg_webshop', '/public/site/images/design/menu/bg_webshop.jpg');	
	preLoadImage('bg_nil', '/public/site/images/design/menu/bg_nil.jpg');		
	preLoadImage('bg_inf', '/public/site/images/design/menu/bg_inf.jpg');			
	preLoadImage('bg_com', '/public/site/images/design/menu/bg_com.jpg');				
}

function changeBackground(obj, id) {
	if(pre_images[id]) {
		obj.style.backgroundImage = 'url(\''+ pre_images[id].src +'\')';
	}
}

function changeImage(obj, id) {
	if(pre_images[id]) {
		obj.src = pre_images[id].src;
	}
}

function activateMenu(id) {
	changeBackground( $('line_'+ id), 'line_'+ id );
	changeBackground( $('img_'+ id), 'img_'+ id +'_over' );
}

function deActivateMenu(id) {
	$('line_'+ id).style.backgroundImage = '';
	changeBackground( $('img_'+ id), 'img_'+ id );	 
}

pre_load_images();
//addLoadEvent(initImages);