function show(ref, make) {
  if (document.getElementById(ref).className != 'show') {
    document.getElementById(ref).className = 'show';
    document.getElementById('hoverbg').style.background = "url('gfx/content_previews/"+make+".jpg')";
    document.getElementById('hoverbg').style.display = 'block';
    document.getElementById('default_summary').style.display = 'none';
  }
}

function hide(ref) {
  document.getElementById(ref).className = '';
  document.getElementById('hoverbg').style.display = 'none';
  document.getElementById('default_summary').style.display = 'block';
}