/*
 * po najeti na obrazek zhoveruje nadpis nad tim
 */
function hover_heading(id) {
  var anchor = document.getElementById(id).getElementsByTagName('h2')[0].getElementsByTagName('a')[0];
  anchor.className = 'active';
}

function hover_heading_out(id) {
  var anchor = document.getElementById(id).getElementsByTagName('h2')[0].getElementsByTagName('a')[0];
  anchor.className = '';
}