// JavaScript Document

function changePic(img, path){
	var bigImg = document.getElementById(img);
	bigImg.src = path;
	markActiveLink(path);
}

function markActiveLink(name){
	resetOldActiveLinks(name);
	var aTag = document.getElementsByName(name)[0];
	aTag.className = "active";
}

function resetOldActiveLinks(actName){
	var aTag = document.getElementsByName(actName)[0];
	
	for(var i=1; i < aTag.parentNode.childNodes.length-1; i++){
		if(aTag.parentNode.childNodes[i].className == "active")
			aTag.parentNode.childNodes[i].className = "normal";
	}
}

function prevNextPic(img, direction){
	var bigImg = document.getElementById(img);
	var navi = bigImg.nextSibling;
	
	for(var i=1; i < navi.childNodes.length-1; i++){
		if(navi.childNodes[i].className == "active"){
			if(i+3*direction > 0 && i+3*direction < navi.childNodes.length-1){
				navi.childNodes[i+2*direction].className = "active";	
				bigImg.src = navi.childNodes[i+2*direction].name;
				navi.childNodes[i].className = "normal";
			}
			break;
		}
	}
}

var imgArray = new Array();
var linkArray = new Array();
var imgHolderId;
var actRotImg;

function initImageRotation(imgString, linkString, id){
	imgArray = imgString.split(",");
	linkArray = linkString.split(",");
	imgHolderId = id;
	actRotImg = randomZahl(0, imgArray.length-1);
}

function imageRotation(){
	var imgHolder = document.getElementById(imgHolderId);
	var imgLink = imgHolder.parentNode;
  	if(actRotImg>=imgArray.length)
  		actRotImg=0;

  	imgHolder.src = imgArray[actRotImg];
	imgLink.href = linkArray[actRotImg];
	actRotImg++;
}

function randomZahl(minVal, maxVal){
   var zufall = Math.round(Math.random() * maxVal-minVal) + minVal;
   return zufall;
}