//Bild breite
var img_width = 0;
//Aktives Bild
var current_img = 0;
//ID des Bildes, das in der mitte ist
var center_img_id = 0;
//Default position von imgStrip
var def_pos_img_strip = 0;
//Aktulle Position des imgStrip
var current_pos_img_strip = 0;
//Status 0 = Scroller inactive | 1 = Scroller aktiv
var scroll_status = 0;
//Anzahl der Bilder
var img_count = 0;


/**
* Init:
* ermittelt die Breite der Bilder.
* ermittelt das erste aktive Bild.
* ermittelt die ID des Bildes das in der mitte ist
* positioniert den imgStrip
* gibt die Bildbeschreibung des ersten Bildes aus
* ---
* @param
* auto => true oder false 
* direction => left oder right
* ---
* by setCookie
*/
function getAttributeAsNumber(attr)
{
	return attr.substr(0,attr.length-2);
}

function shiftLeftArray(arr, start)
{
   if(!arr) return;
   if(start<0 || start> arr.length-1) return;
   var tmp = arr[start];
   for(i = start; i<arr.length-1; ++i){
       arr[i] = arr[i+1];	
   }
   arr[arr.length-1] = tmp;
}


function shiftRightArray(arr, start)
{
   if(!arr) return;
   if(start<0 || start>arr.length-1) return;
   var tmp = arr[arr.length-1];
   for(i = arr.length-1; i>=start; --i){
       arr[i] = arr[i-1];	
   }
   arr[start] = tmp;
}


function alertArr(arr, start)
{
   if(!arr) return;
   if(start<0 || start> arr.length-1) return;
   var tmp = arr[arr.length-1];
   var str = "";
   for(i = start; i<arr.length; ++i){
       str += "["+ i + "]=" + arr[i] + "\n";
   }
   alert(str);
}

function getDefPos(idx)
{
    leftWidth = 0;
	for( i = 1; i<img_names.length; ++i){
		if(i<idx){
			leftWidth += img_width[i]+1; 
		}
	}
	return imgStripLeft-leftWidth;
}

function init(startImgIdx)
{
	imgViewerWidth = getAttributeAsNumber(document.getElementById("imgViewer").style.width);
	imgStripLeft = getAttributeAsNumber(document.getElementById("imgStrip").style.left);
	
	img_idz = new Array();
	img_width = new Array();
	leftWidth = 0;
	
    for( i = 0; i<img_names.length; ++i){
		img_idz[i] = i;
		if(i>0){
	        img_width[i] = document.images[img_names[i]].width;
			if(i<startImgIdx){
				leftWidth += img_width[i]+1; 
			}
		}
	}
	curr_img_width = document.images[img_names[1]].width+1;

	center_img_id = Math.floor(img_names.length/2);
	img_count = img_names.length-1;
	if(startImgIdx <2)
	   startImgIdx = img_names.length-1;
	current_img = startImgIdx; //center_img_id;
	//v_images = imgViewerWidth/ curr_img_width;
	//non_v_images = (img_names.length-1)-v_images;
	//x = Math.floor(non_v_images / 2);
	def_pos_img_strip = imgStripLeft - (leftWidth);
	imgStrip.style.left = def_pos_img_strip;
	current_pos_img_strip = def_pos_img_strip;
	if(document.all["imgDescription"])
		document.all["imgDescription"].innerHTML = img_descriptions[center_img_id]; 

}

/**
* scroll_left:
* Bewegt imgStrip nach links
* ---
* by setCookie
*/
function scroll_left(){
	
	if(current_pos_img_strip > (def_pos_img_strip - curr_img_width)){
		current_pos_img_strip = current_pos_img_strip - Math.floor(curr_img_width/10);
		imgStrip.style.left = current_pos_img_strip;
		window.setTimeout("scroll_left()",speed);
	}else{
		
		scroll_status = 0;
		switch_images_left();
		def_pos_img_strip = getDefPos(current_img);

		imgStrip.style.left = def_pos_img_strip;
		current_pos_img_strip = def_pos_img_strip;
	}
}

/**
* scroll_right:
* Bewegt imgStrip nach rechts
* ---
* by setCookie
*/
function scroll_right(){
	if(current_pos_img_strip < (def_pos_img_strip + curr_img_width)){
		current_pos_img_strip = current_pos_img_strip + Math.floor(curr_img_width/10);
		imgStrip.style.left = current_pos_img_strip;
		window.setTimeout("scroll_right()",speed);
		alert
	}else{
		
		scroll_status = 0;
		switch_images_right();
        def_pos_img_strip = getDefPos(current_img);
		imgStrip.style.left = def_pos_img_strip;
		current_pos_img_strip = def_pos_img_strip;
	}
}


/**
* switch_images_right:
* Verschiebt alle Bilder um eins nach rechts
* ---
* by setCookie
*/
function switch_images_right(){
	
	img_src = new Array();
	var tmp = document.images[img_names[img_names.length-1]].src;
	var tmpWidth = document.images[img_names[img_names.length-1]].width;
	for(i=img_names.length-1;i>1;i--){
		document.images[img_names[i]].src = document.images[img_names[i-1]].src;
		document.images[img_names[i]].width = document.images[img_names[i-1]].width;
	}
	document.images[img_names[1]].src = tmp;
	document.images[img_names[1]].width = tmpWidth;
	shiftRightArray(img_idz, 1);
	shiftRightArray(img_width, 1);
	//alertArr(img_width, 1);
	curr_img_width = document.images[img_names[current_img]].width;
}

/**
* switch_images_left:
* Verschiebt alle Bilder um eins nach links
* ---
* by setCookie
*/
function switch_images_left(){
	
	img_src = new Array();
	var tmp =document.images[img_names[1]].src;
	var tmpWidth =document.images[img_names[1]].width;
	for(i=1;i<img_names.length-1;i++){
		document.images[img_names[i]].src = document.images[img_names[i+1]].src;
		document.images[img_names[i]].width = document.images[img_names[i+1]].width;
	}
	document.images[img_names[img_names.length-1]].src = tmp;
	document.images[img_names[img_names.length-1]].width = tmpWidth;
	shiftLeftArray(img_idz, 1);
	shiftLeftArray(img_width, 1);
	//alertArr(img_width, 1);
	curr_img_width = document.images[img_names[current_img]].width;

}

/**
* scroll:
* Argumente direction = left | right
* Setzt die neue aktive Bild Nr.
* Started das scrollen und den fader.
* ---
* by setCookie
*/
function scroll(direction){
	
	if(scroll_status == 0){
		
		scroll_sleep = 0;
	}

	if(!direction){
	
		direction = as_direction;
	}
	if(direction == "right" && scroll_sleep == 0){
		
		scroll_sleep = 1;		
		scroll_status = 1;
    	curr_img_width = document.images[img_names[current_img-1]].width+1;

		scroll_right();
		center_img_id--;
		if(center_img_id == 1){			
			center_img_id = img_names.length-1;
		}
		
	}else if(direction == "left" && scroll_sleep == 0){
		
		scroll_sleep = 1;
		scroll_status = 1;
    	curr_img_width = document.images[img_names[current_img]].width+1;

		scroll_left();
		center_img_id++;
		if(center_img_id == img_names.length){			
			center_img_id = 1;
		}
	}
	if(document.all["imgDescription"])
		document.all["imgDescription"].innerHTML = img_descriptions[center_img_id];
	
}