function gotoUrl(url) {
 document.location.href=url;
}

var currentId = 0;

function showImageLayer(id) {
 
 document.getElementById('imageLayer').className = 'imageLayerShow';
 document.getElementById('imageFrame').className = 'imageFrameShow';
 
 currentId = id;
 
 document.getElementById('imageLayerImage').src = imageArray[id];
 document.getElementById('imageLayerDescription').innerHTML = textArray[id];
 
}
function next() {
 if (currentId < count) {
  return showImageLayer(currentId+1);
 }
 if (currentId == count) {
  return showImageLayer(0);
 }
}
function previous() {
 if (currentId > 0) {
  return showImageLayer(currentId-1);
 }
 if (currentId == 0) {
  return showImageLayer(count);
 }
}
function hideImageLayer() {
 document.getElementById('imageLayer').className = 'imageLayerHidden';
 document.getElementById('imageFrame').className = 'imageFrameHidden';
}

function showProgrammCategory(category) {
 /* hide all */
 for (index in konzerte) {
  try { document.getElementById(konzerte[index]).className = 'progammEntryHidden'; } catch(e) {}
 }
 for (index in ausstellungen) {
  try { document.getElementById(ausstellungen[index]).className = 'progammEntryHidden'; } catch(e) {}
 }
 for (index in lesungen) {
  try { document.getElementById(lesungen[index]).className = 'progammEntryHidden'; } catch(e) {}
 }
 for (index in kurse) {
  try { document.getElementById(kurse[index]).className = 'progammEntryHidden'; } catch(e) {}
 }
 for (index in maedchen) {
  try { document.getElementById(maedchen[index]).className = 'progammEntryHidden'; } catch(e) {}
 }
 document.getElementById('linkKonzerte').className = '';
 document.getElementById('linkAusstellungen').className = '';
 document.getElementById('linkLesungen').className = '';
 document.getElementById('linkKurse').className = '';
 document.getElementById('linkMaedchen').className = '';
 document.getElementById('linkAlle').className = '';
 
 /* show selected */
 if (category === 'konzerte') {
  document.getElementById('linkKonzerte').className = 'contentFilterLinksActive';
  for (index in konzerte) { try { document.getElementById(konzerte[index]).className = 'progammEntry'; } catch(e) {} }
 }
 if (category === 'ausstellungen') {
  document.getElementById('linkAusstellungen').className = 'contentFilterLinksActive';
  for (index in ausstellungen) { try { document.getElementById(ausstellungen[index]).className = 'progammEntry'; } catch(e) {} }
 }
 if (category === 'lesungen') {
  document.getElementById('linkLesungen').className = 'contentFilterLinksActive';
  for (index in lesungen) { try { document.getElementById(lesungen[index]).className = 'progammEntry'; } catch(e) {} }
 }
 if (category === 'kurse') {
  document.getElementById('linkKurse').className = 'contentFilterLinksActive';
  for (index in kurse) { try { document.getElementById(kurse[index]).className = 'progammEntry'; } catch(e) {} }
 }
 if (category === 'maedchen') {
  document.getElementById('linkMaedchen').className = 'contentFilterLinksActive';
  for (index in maedchen) { try { document.getElementById(maedchen[index]).className = 'progammEntry'; } catch(e) {} }
 }
 if (category === 'alle') {
  for (index in konzerte) { try { document.getElementById(konzerte[index]).className = 'progammEntry'; } catch(e) {} }
  for (index in ausstellungen) { try { document.getElementById(ausstellungen[index]).className = 'progammEntry'; } catch(e) {} }
  for (index in lesungen) { try { document.getElementById(lesungen[index]).className = 'progammEntry'; } catch(e) {} }
  for (index in kurse) { try { document.getElementById(kurse[index]).className = 'progammEntry'; } catch(e) {} }
  for (index in maedchen) { try { document.getElementById(maedchen[index]).className = 'progammEntry'; } catch(e) {} }
  document.getElementById('linkAlle').className = 'contentFilterLinksActive';
 }
}