var loadingImg = '/images/loading.gif';
var zoomlink = null;
var cur = 4;
var nbsite = 10;

function initZoomBox() {
	var loading = new Image();
	loading.src = loadingImg;
	var prev = document.getElementById('prevzoom');
	prev.onclick = function () { getZoom(-1); return false; }
	var next = document.getElementById('nextzoom');
	next.onclick = function () { getZoom(+1); return false; }
	zoomlink = document.getElementById('zoomlink');
	cur = document.getElementById('zoomcur').value;
}

function getZoom(exp) {
	cur = (cur)*1 + (exp)*1;
	if(cur<=0) cur = nbsite; else if(cur>nbsite) cur=1;
	var zoomimg = document.getElementById('zoomimg');
	zoomimg.src = loadingImg;
	var zoomcpt = document.getElementById('zoomcaption');
	zoomcpt.innerHTML = '&nbsp;<br />&nbsp;';

	if ( window.XMLHttpRequest ) {
		ajaxobj = new XMLHttpRequest();   
	} else if ( window.ActiveXObject ) {
		ajaxobj = new ActiveXObject( 'Microsoft.XMLHTTP' );   
	} else {
		alert( 'Votre navigateur ne supporte pas les objets XMLHTTPRequest...' );   
		return;
	}
	ajaxobj.open( 'GET', '/includes/ajax/zoom.php?id='+cur, true );
	ajaxobj.onreadystatechange = CallBackRequest;
	ajaxobj.send( null );


}


function CallBackRequest() {
	if ( ajaxobj.readyState == 4 ) {
		var items = ajaxobj.responseText.split('#');
		loader = new Image();
		loader.onload = function() {
			var zoomimg = document.getElementById('zoomimg');
			zoomimg.src = loader.src;
			var zoomcpt = document.getElementById('zoomcaption');
			zoomcpt.innerHTML = items[1];
			zoomlink.href = './realisations/rea'+cur+'.html';
		}
		loader.src = items[0];
	}
}

function addZoomLoadEvent(func) {	
	var oldonload = window.onload;
	if (typeof window.onload != 'function'){
    	window.onload = func;
	} else {
		window.onload = function(){
		oldonload();
		func();
		}
	}
}

addZoomLoadEvent(initZoomBox);