function init(folder, items, no){
	if(no == null){
		var no = Math.round(Math.random()*items)+1;
		document.getElementById("main_image").innerHTML = "<img src=\"resources/" + folder + "/image_" + no + ".jpg\" alt=\"Sample image\" />";
	}else{
		document.getElementById("main_image").innerHTML = "<img src=\"resources/" + folder + "/image_" + no + ".jpg\" alt=\"Sample image\" />";
	}
	for(var i=1; i<=items; i++){
		var html = "<div class=\"tab\">"
		html += "<a href=\"javascript:void(0);\" onclick=\"switchMainImage('resources/" + folder + "/image_" + i + ".jpg');\">"
		html += "<img src=\"images/subnav_" + i + ".png\" alt=\"View image " + i + "\" />"
		html += "</a>"
		html += "</div>"
		document.getElementById("sub_nav_1").innerHTML += html
	};
};

function switchMainImage(i){
	document.getElementById("main_image").innerHTML = "<img src=\"" + i + "\" alt=\"Sample image\" />";
};