function background() {

	var backgroundCookie = GetCookie("background_internet");
	
    var backgroundImg = document.getElementById("bg_img");
	if(backgroundCookie) {
		 backgroundImg.src = backgroundCookie;
	} else {
		randomnumber=Math.floor(Math.random()*4);
		
		//backgroundImg.src = "fileadmin/site_internet/image/accueil_fille.jpg";
		if (randomnumber==1){
			backgroundImg.src = "fileadmin/site_internet/image/accueil_fille.jpg";
		}
		else if (randomnumber==2){
			backgroundImg.src="fileadmin/site_internet/image/body.jpg";
		}
		else if (randomnumber==3){
			backgroundImg.src="fileadmin/site_internet/image/kite.jpg";
		}
		else {
			backgroundImg.src="fileadmin/site_internet/image/accueil_fille.jpg";
		}
		var pathname=location.pathname;
		var myDomain=pathname.substring(0,pathname.lastIndexOf('/')) +'/';
		SetCookie("background_internet", backgroundImg.src, null, '/');
	}
	
}

function SetCookie (name, value) {
	var argv=SetCookie.arguments;
	var argc=SetCookie.arguments.length;
	var expires=(argc > 2) ? argv[2] : null;
	var path=(argc > 3) ? argv[3] : null;
	var domain=(argc > 4) ? argv[4] : null;
	var secure=(argc > 5) ? argv[5] : false;
	document.cookie=name+"="+escape(value)+
		((expires==null) ? "" : ("; expires="+expires.toGMTString()))+
		((path==null) ? "" : ("; path="+path))+
		((domain==null) ? "" : ("; domain="+domain))+
		((secure==true) ? "; secure" : "");
}

function getCookieVal(offset) {
	var endstr=document.cookie.indexOf (";", offset);
	if (endstr==-1)
      		endstr=document.cookie.length;
	return unescape(document.cookie.substring(offset, endstr));
}
function GetCookie (name) {
	var arg=name+"=";
	var alen=arg.length;
	var clen=document.cookie.length;
	var i=0;
	while (i<clen) {
		var j=i+alen;
		if (document.cookie.substring(i, j)==arg)
                        return getCookieVal (j);
                i=document.cookie.indexOf(" ",i)+1;
                        if (i==0) break;}
	return null;
}