function toggle_search_param_div(div_id) {
    if(document.getElementById(div_id).style.display == 'none') {
      document.getElementById(div_id).style.display = 'block';
      document.getElementById('icon_' + div_id).src = '/images/hide.png';
    } else {
      document.getElementById(div_id).style.display = 'none';
      document.getElementById('icon_' + div_id).src = '/images/expand.png';
    }
  }