// SIMPLE SEARCH SORT
function bet_simple_sort() {
  $type = Params::getParam('sOrder');           // date - price
  $order = Params::getParam('iOrderType');      // asc - desc

  $orders = osc_list_orders();

  //$html  = '<input type="hidden" name="sOrder" id="sOrder" val="' . $type . '"/>';
  //$html  = '<input type="hidden" name="iOrderType" id="iOrderType" val="' . $order . '"/>';

  $html  = '<select class="orderSelect" id="orderSelect" name="orderSelect">';
 
  foreach($orders as $label => $spec) {
    $selected = '';
    if( $spec['sOrder'] == $type && $spec['iOrderType'] == $order ) {
      $selected = ' selected="selected"';
    }
    $html .= '<option' . $selected . ' data-type="' . $spec['sOrder'] . '" data-order="' . $spec['iOrderType'] . '">' . $label . '</option>';
  }

  $html .= '</select>';
  return $html;
}

Not working

@umimo
It is possible, sorting is tuff to do in one box, as osclass expects 2 inputs for that.