function openPreview(filename, alias, file_name_big) {
  
  $('#big_img_div').hide();
  $('#preview_img').attr('src', filename);
  jQuery('li[@id^="paper_"]').removeClass('red');//.each( function() { jQuery(this).show(); });
  jQuery('li[@id^="paper_"]').addClass('blue');
  //jQuery('li[@id^="paper_active_"]').hide();//.each( function() { jQuery(this).hide(); });
  
  $('#paper_' + alias).addClass('red');//.hide();
  $('#paper_' + alias).removeClass('blue');
  //$('#paper_active_' + alias).show();
  
  $('#big_img').attr('src', file_name_big);
}

function openBig() {
  $('#big_img_div').animate({ opacity: "show" }, "slow"); //show();
}