function wait_change_news(nbPage,nbNews,check_time) {

	if (document.getElementById("news"+(nbNews-1))==null){
		setTimeout('wait_change_news('+nbPage+','+nbNews+','+check_time+')',check_time);
	} else {
		change_news(nbPage,nbNews);
	}

}


function change_news(nbPage,nbNews)
{
	document.getElementById("loading").style.display="block";

    var xhr=null;
    
    if (window.XMLHttpRequest) { 
        xhr = new XMLHttpRequest();
    }
    else if (window.ActiveXObject) 
    {
        xhr = new ActiveXObject("Microsoft.XMLHTTP");
    }
	
    //on définit l'appel de la fonction au retour serveur
    xhr.onreadystatechange = function() { alert_ajax(xhr,nbPage,nbNews); };
    
    xhr.open("GET", "./ajax_news.php?nbPage="+nbPage+"&nbNews="+nbNews, true);
    xhr.send(null);
}

function alert_ajax(xhr,nbPage,nbNews)
{
	if (xhr.readyState==4) 
	{
		document.getElementById("loading").style.display="none";
		
		var media;
		var url;
		var contenu;
		var nbNewsTot;

		var docXML= xhr.responseXML;
		
		nbNewsTot=docXML.getElementsByTagName("nbNewsTot")[0].firstChild.data;
		
		var items = docXML.getElementsByTagName("news")
		for (i=0;i<items.length;i++) { // pour chaque news
			media="";
			url="";
			for (j=0;j<items.item(i).childNodes.length;j++) { // on récupère le noeud news et url
				if (items.item(i).childNodes.item(j).firstChild!=null) {
					if (items.item(i).childNodes.item(j).tagName=="media")
						media=items.item(i).childNodes.item(j).firstChild.data;
						
					if (items.item(i).childNodes.item(j).tagName=="url")
						url=items.item(i).childNodes.item(j).firstChild.data;
				}
			}

			contenu="";
			if (url!="")
				contenu+='<a href="'+url+'" target="_blank">';
			
			if (media.substr(media.length-3,3).toLowerCase()=="swf") {
				contenu+='<object classid="clsid:D27CDB6E-AE6D-11cf-96B8-444553540000" codebase="http://download.macromedia.com/pub/shockwave/cabs/flash/swflash.cab#version=7,0,19,0" width="314" height="118">'+"\n";
				contenu+='<param name="movie" value="'+media+'">'+"\n";
				contenu+='<param name="quality" value="high">'+"\n";
				contenu+='<embed src="'+media+'" quality="high" pluginspage="http://www.macromedia.com/go/getflashplayer" type="application/x-shockwave-flash" width="314" height="118"></embed>'+"\n";
				contenu+='</object>'+"\n";
			} else
				contenu+='<img src="'+media+'" width="314" height="118" border="0">';
			
			if (url!="")
				contenu+='</a>';
			
			// changement de page
			if (i==items.length-1) { // après la dernière news, on affiche les liens vers les autres pages
				contenu+="<br/>";
				if (nbPage!=0) // pas la 1ere page => affichage du lien
					contenu+="<a href='javascript:change_news("+(nbPage-1)+","+nbNews+");'>Prec</a>";
				else 
					contenu+=" &nbsp; &nbsp; &nbsp;";
				
				contenu+=" &nbsp; &nbsp;";
				
				if (nbPage!=Math.ceil(nbNewsTot/nbNews)-1) // pas la derniere page => affichage du lien
					contenu+="<a href='javascript:change_news("+(nbPage+1)+","+nbNews+");'>Suiv</a>";
			}
			
			document.getElementById("news"+i).innerHTML=contenu;
		}
		for (i;i<nbNews;i++) { // on enleve les news précédente pour la derniere page
			document.getElementById("news"+i).innerHTML="";
		}
		
	}
}