function image_switch(dir) {
	var new_index = current_index+dir;	
	
	if (new_index < 0) new_index = all_previews.length-1;
	if (new_index >= all_previews.length) new_index = 0;	

	var new_image = all_previews[new_index];
	current_index = new_index;
	showImage(new_image[0], new_image[1], new_image[2]);
}

function showImage(src,image_id, bu) {
	if (activeImage) {
		document.getElementById(activeImage).className = "";
	}
	document.images["immo_image"].src = src;
	var obj = document.getElementById(image_id);
	obj.className = "active";
	
	var large = src.replace(/preview_/, "");
	document.getElementById("immo_large").href=large;
	document.getElementById("immo_large_bu").innerHTML=bu;
	
	activeImage = image_id;
}