function submit_search() {
  if ( document.getElementById('query').value == 'Suchbegriff(e) eingeben' ) {
    document.getElementById('query').value = '';
  }
  if ( document.getElementById('search_startdate').value == 'von (TT/MM/JJJJ)*' ) {
    document.getElementById('search_startdate').value = '';
  }
  if ( document.getElementById('search_enddate').value == 'bis (TT/MM/JJJJ)*' ) {
    document.getElementById('search_enddate').value = '';
  }
  return true;
}