function switchFoto(target_id, foto_url, foto_url2, div){
	var target = document.getElementById("img_"+target_id);
	var targetLink = document.getElementById("imgLink_"+target_id);
	if (target != null && targetLink != null){
		var base = "http://www.bouwbedrijfhuiskes.nl/uploads/uw_woning_bouwen/basisontwerpen/";
		if (target.src == base + "thumbs/" +foto_url){
			target.src = base+"thumbs/"+foto_url2;
			targetLink.href = base+foto_url2;
		} else {
			target.src = base+"thumbs/"+foto_url;
			targetLink.href = base+foto_url;
		}
	}
	var html = div.innerHTML;
	if (html == ">>"){
		div.innerHTML = "<<";
	} else {
		div.innerHTML = ">>";
	}
}