var current_photo_index = 0;

function set_photo(index)
{
 var last_button = getNode('photo_menu_'+current_photo_index);
 var pressed_button = getNode('photo_menu_'+index);
 var big_photo = getNode('big_photo');
 
 if(last_button)
 { 
  if(pressed_button)
  {
   if(big_photo)
   {
    last_button.parentNode.parentNode.className = 'snl_box';
    pressed_button.parentNode.parentNode.className = 'sn_box';
   
    big_photo.src = '';
    big_photo.src = photo_list[0][index];
    current_photo_index = index;
   }
  }
 }
}

function show_photo()
{
 show_layer(photo_list[1][current_photo_index]);
}

function hide_layer()
{
 hideElement(getNode('overlay'));
 hideElement(getNode('overlay_holder'));
 getNode('overlay_holder_image').src = ' '; 
}

function center_layer_image(holder)
{
 var viewport_rect = getViewportRectangle();
 var holder_rect = getElementRectangle(holder);
  
 var center = centerRectangleInRectangle(holder_rect,viewport_rect);
 center.y += getScrollY();
  
 moveNode(holder,center);
}

function show_layer(img_src)
{
 var overlay = getNode('overlay');
 var holder = getNode('overlay_holder');
 var image = getNode('overlay_holder_image');
 
 if(overlay)
 {
  if(holder)
  {
   if(image)
   {
    image.onload = function()
    {
     resizeElement(overlay,getDocumentRectangle());
     showElement(overlay,true,true);
     showElement(holder,true,true);
     center_layer_image(holder);
     
     image.onload = function(){};
    }
        
    image.src = ' ';
    image.src = img_src;

    showElement(overlay,true,false);
    showElement(holder,true,false);
   }
  }
 }
}