var _overlay_imgs = new Array();
var _overlay_txts = new Array();
var _overlay_current = -1;
var _overlay_div = null;
var _overlay_img = null;
var _overlay_txt_close = "schließen";
var _overlay_txt_previous = "vorheriges";
var _overlay_txt_next = "nächstes";



function _overlay_init(close, previous, next)
{
  _overlay_txt_close = close;
  _overlay_txt_previous = previous;
  _overlay_txt_next = next;
}



function _overlay_open(imgs, txts)
{
  var div;
  var img;
  var a;
  var IE6 = false /*@cc_on || @_jscript_version < 5.7 @*/;

  _overlay_imgs = imgs;
  _overlay_txts = txts;
  _overlay_current = 0;
  _overlay_img = document.createElement("img");
  _overlay_div = document.createElement("div");
  _overlay_div.id = "overlay";

  div = document.createElement("div");
  div.className = "overlay_img";
  div.appendChild(_overlay_img);
  _overlay_div.appendChild(div);

  img = document.createElement("img");
  img.src = "style/close.png";
  img.alt = _overlay_txt_close;
  img.title = _overlay_txt_close;
  a = document.createElement("a");
  a.id = "overlay_close";
  a.className = "overlay";
  a.href = "";
  a.onclick = function() {_overlay_close(); return false;};
  a.appendChild(img);
  _overlay_div.appendChild(a);

  _overlay_refresh();

  if(IE6)
  {
    _overlay_div.style.top = document.getElementById('main').scrollTop + 50 + 'px';
  }
  document.getElementById("main").appendChild(_overlay_div); 
}



function _overlay_refresh()
{
  var img;
  var a;

  _overlay_img.src = _overlay_imgs[_overlay_current];
  _overlay_img.alt = _overlay_txts[_overlay_current];
  if(_overlay_imgs.length > 1)
  {
    if(_overlay_current > 0)
    {
      if(!document.getElementById("overlay_previous"))
      {
	img = document.createElement("img");
	img.src = "style/previous.png";
	img.alt = _overlay_txt_previous;
	img.title = _overlay_txt_previous;
	a = document.createElement("a");
	a.id = "overlay_previous";
	a.className = "overlay";
	a.href = "";
        a.onclick = function() {_overlay_previous(); return false;};
	a.appendChild(img);
	_overlay_div.appendChild(a);
      }
    }
    else
    {
      if(a = document.getElementById("overlay_previous")) _overlay_div.removeChild(a);
    }

    if(_overlay_current < _overlay_imgs.length - 1)
    {
      if(!document.getElementById("overlay_next"))
      {
	img = document.createElement("img");
	img.src = "style/next.png";
	img.alt = _overlay_txt_next;
	img.title = _overlay_txt_next;
	a = document.createElement("a");
	a.id = "overlay_next";
	a.className = "overlay";
	a.href = "";
        a.onclick = function() {_overlay_next(); return false;};
	a.appendChild(img);
	_overlay_div.appendChild(a);
      }
    }
    else
    {
      if(a = document.getElementById("overlay_next")) _overlay_div.removeChild(a);
    }

  }
}



function _overlay_previous()
{
  _overlay_current -= 1;
  _overlay_refresh();
}



function _overlay_next()
{
  _overlay_current += 1;
  _overlay_refresh();
}



function _overlay_close()
{
  document.getElementById("main").removeChild(_overlay_div);
}