var bildpfad = 'images/';

var setCoverBody = function() {
  var p = pageoffset();
  $('coverBody').style.height = p.absY+'px';
  $('coverBody').style.width =  p.absX+'px';
}

var adjustCoverBody = function() {
  var p = pageoffset();
  
  var topMargin = ((p.absY - $('imageZoom').offsetHeight)/2 - 5);
  if(topMargin < 0) topMargin = 0;
  $('imageZoom').style.top = topMargin + 'px';
  var leftMargin = ((p.absX - $('imageZoom').offsetWidth)/2 - 10);
  if(leftMargin < 0) leftMargin = 0;
  $('imageZoom').style.left =  leftMargin + 'px';
}

var mouseover = {
  generic: function(event) {
    this.style.cursor = 'pointer';
  }
};

var mouseout = {
  generic: function(event) {
    this.style.cursor = 'auto';
  }
};

var mouseclick = {
  generic: function(event) {
    var p = pageoffset();
    setCoverBody();

    $('image').src = this.src;
    var topMargin = ((p.absY - this.height)/2 - 5);
    //var topMargin = ((p.scrollY + 50)/2);
    if(topMargin < 0) topMargin = 0;
    $('imageZoom').style.top = topMargin + 'px';
    var leftMargin = ((p.absX - this.width)/2 - 10);
    if(leftMargin < 0) leftMargin = 0;
    $('imageZoom').style.left =  leftMargin + 'px';
    $('coverBody').style.display = 'block';
    $('imageZoom').style.display = 'block';
  }
};

var initimageZoom = function() {
  var images = document.getElementsByTagName('img');
  for(var i=0; i<images.length;i++) {
    var classNames = images[i].className.split(' ');
    for(var j=0; j<classNames.length; j++) {
      if(classNames[j] == 'imageZoom') {
        images[i].id = 'imageZoom' + i;
        images[i].style.cursor = 'hand';
        var image = new Image();
        
        // src-Attribut des grossen Bildes bestimmen
        image.src = images[i].src.replace(/_kl./g, "_gr.");
        Event.observe(images[i].id, 'mouseover', mouseover.generic.bindAsEventListener(images[i]));
        Event.observe(images[i].id, 'mouseout', mouseout.generic.bindAsEventListener(images[i]));
        Event.observe(images[i].id, 'click', mouseclick.generic.bindAsEventListener(image));
      }
    }
  }
}

var closecoverBody = function() {
  $('image').src = '';
  $('imageZoom').style.display = 'none';
  $('coverBody').style.display = 'none';
}

window.onresize = function() {
  setCoverBody();
  adjustCoverBody();
}

window.onscroll = function() {
  setCoverBody();
  adjustCoverBody();
}