$(document).ready(function(){
	if(typeof img!='undefined' && 1<img.length) {
			$("#top .back").click(function(){ change_img("back"); return false; });		
			$("#top .next").click(function(){ change_img("next"); return false; });
	}
});

function change_img(type) {
	var len = img.length;
	var akt = $("#top #akt").attr("src");
	var pos = -1;
	for(var i=0; i<len; i++) {
		if(img[i]==akt) {
			pos = i;
			break;
		}
	}
	if(pos!=-1) {
		$("#top .back").css("display","none");
		$("#top .next").css("display","none");
		$("#top #akt").replaceWith("<div class=\"\load\">&nbsp;</div><img src=\"images/blank.gif\" alt=\"\" width=\"1\" height=\"1\" id=\"akt\" />");
		if(type=='back') {
			pos = (pos==0) ? len-1 : pos-1;
		} else {
			pos = (pos+1==len) ? 0 : pos+1;
		}		
		var objImagePreloader = new Image();
		objImagePreloader.onload = function() {
			var w = objImagePreloader.width;
			var h = objImagePreloader.height;
			$('#top #akt').attr({'src':img[pos],'alt':alt[pos],'title':alt[pos]});
			$('#top #akt').attr('width',w);
			$('#top #akt').attr('height',h);
			if(h<=402) {
				$("#top .back img").attr("src","images/btn_back.png");
			} else {
				$("#top .back img").attr("src","images/btn_back_white.png");	
			}
			if(w<=402 || h<=402) {
				$("#top .next img").attr("src","images/btn_next.png");
			} else {
				$("#top .next img").attr("src","images/btn_next_white.png");	
			}
			$('#top .load').remove();
			$('#top #akt').animate({ width: w, height: h },"slow", function() { $('#top #akt').show(); });
			$("#top .back").css("display","block");
			$("#top .next").css("display","block");
			objImagePreloader.onload=function(){};
		};
		objImagePreloader.src = img[pos];
	}
}