function loadSiblings(cat_id, item_id, sib_page){

	file = "/share/php/ajax.php";

	//add parameters to the request url
	url = file + "?action=siblings&cat_id=" + cat_id + "&item_id=" + item_id + "&sibling_page=" + sib_page;

	//create objects
	container = document.getElementById('sibling_list');
	loader = document.getElementById('dvloader');

	//hide current content and display progress image
	show_progress(container, loader);

	//create object
	if (window.XMLHttpRequest){
		// code for IE7+, Firefox, Chrome, Opera, Safari
		xmlhttp=new XMLHttpRequest();
	}
	else{
		// code for IE6, IE5
		xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
	}

	//load new content and hide progress image
	xmlhttp.onreadystatechange=function()
	{
		if(xmlhttp.readyState == 4){
			document.getElementById('siblings_cont').innerHTML=xmlhttp.responseText;
			hide_progress(container, loader);
		}
	}

	xmlhttp.open("GET",url,true);
	xmlhttp.send(null);
}

/*Auxiliary function to display progress image while the content is loaded*/
function show_progress(container, loader){
	loader.style.display = 'block';
	container.style.visibility = 'hidden';
}

/*Auxiliary function to hide progress image once request is completed */
function hide_progress(container, loader){
	loader.style.display = 'none';
	container.style.visibility = 'visible';
}