function keepMeAlive() {
			var response;
			ajaxObjects = new Array();
			var ajaxIndex = ajaxObjects.length;
			ajaxObjects[ajaxIndex] = new sack();
			var url = 'controller/plugins/ajax/keepalive.php';
			ajaxObjects[ajaxIndex].requestFile = url;
			ajaxObjects[ajaxIndex].onCompletion = function() { ajaxObjects[ajaxIndex].response;  };	
			ajaxObjects[ajaxIndex].runAJAX();		
	}
	
	window.setInterval("keepMeAlive()", 100000);

	function getRandomFoto(action)
	{
			var response;
			ajaxObjects = new Array();
			var ajaxIndex = ajaxObjects.length;
			ajaxObjects[ajaxIndex] = new sack();
			var url = 'controller/plugins/ajax/get_random_image.php?id='+document.getElementById('current_photo_id').value+'&action='+action;
			ajaxObjects[ajaxIndex].requestFile = url;
			ajaxObjects[ajaxIndex].onCompletion = function() 
			{ 
				response = ajaxObjects[ajaxIndex].response;
				response = response.split('|')

				// document.getElementById('frame').style.background = "url("+response[0]+") no-repeat center center;"; 

				document.getElementById('current_photo_id').innerHTML = '<div id="frame" style="background: url('+response[0]+') no-repeat center center;"></div>';
				document.getElementById('current_photo_id').href = '?nav=photos&subnav=photo_view&photo_id='+response[1];
				document.getElementById('photo_title').innerHTML = response[2];
				document.getElementById('photo_description').innerHTML = response[3];
				document.getElementById('photo_username').innerHTML = response[4];
				document.getElementById('photo_country').innerHTML = response[5];						
			};	
			ajaxObjects[ajaxIndex].runAJAX();	
	}

	function blocking(nr)
	{
		if (document.layers)
		{
			current = (document.layers[nr].display == 'none') ? 'block' : 'none';
			document.layers[nr].display = current;
		}
		else if (document.all)
		{
			current = (document.all[nr].style.display == 'none') ? 'block' : 'none';
			document.all[nr].style.display = current;
		}
		else if (document.getElementById)
		{
			vista = (document.getElementById(nr).style.display == 'none') ? 'block' : 'none';
			document.getElementById(nr).style.display = vista;
		}
	}	
	
	function showLoader()
	{
		blocking('uploaden');
		new Effect.Center('loader');
		new Effect.Appear('loader');
	}
	
	function showError(element)
	{
		new Effect.Center('foutmelding');
		new Effect.Appear('foutmelding');
		blocking(element);
	}		
	
	function closeError(element)
	{
		new Effect.Fade('foutmelding');
		blocking(element);
	}		
	
	function blocking(nr)
	{
		if (document.layers)
		{
			current = (document.layers[nr].display == 'none') ? 'block' : 'none';
			document.layers[nr].display = current;
		}
		else if (document.all)
		{
			current = (document.all[nr].style.display == 'none') ? 'block' : 'none';
			document.all[nr].style.display = current;
		}
		else if (document.getElementById)
		{
			vista = (document.getElementById(nr).style.display == 'none') ? 'block' : 'none';
			document.getElementById(nr).style.display = vista;
		}
	}
	
	function get_object(object_id) {
		if(document.getElementById && document.getElementById(object_id)) {
			return document.getElementById(object_id);
		} else if(document.all && document.all(object_id)) {
			return document.all(object_id);
		} else if(document.layers && document.layers[object_id]) {
			return document.layers[object_id];
		} else {
			return false;
		}
	}
	
	function show(elm_id) {
		var elm = get_object(elm_id);
		if(elm) {
			elm.style.visibility = "visible";
		}
	}
	
	function hide(elm_id) {
		var elm = get_object(elm_id);
		if(elm) {
			elm.style.visibility = "hidden";
		}
	}
	
	function change_display(elm_id, display) {
		var elm = get_object(elm_id);
		if(elm) {
			elm.style.display = display;
		}
	}
	
	function select_all(name) {
		for (i = 0; i < name.length; i++) {
			name[i].checked = true ;
		}
	}
	
	function deselect_all(name) {
		for (i = 0; i < name.length; i++) {
			name[i].checked = false ;
		}
	}