/**
  * Gets a nice grid in html string
  * @param string grid name (important to create css)
  * @param array header content
  * @param array array with the information to show
  * @param array $paging_options Keys are:
  * 					'per_page_default' = items per page when switching from
  * 										 full-	list to per-page-view
  * 					'per_page' = number of items to show per page
  * 					'page_nr' = The page to display
  * 					'hide_navigation' =  true to hide the navigation
  * @param array $query_vars Additional variables to add in the query-string
  * @param array $form actions Additional variables to add in the query-string
  * @param mixed An array with bool values to know which columns show. i.e:
  *  $visibility_options= array(true, false) we will only show the first column
  * 	Can be also only a bool value. TRUE: show all columns, FALSE: show nothing
  * @param bool  true for sorting data or false otherwise
  * @param array grid classes
  * @return 	string   html grid
  */
 public static function return_sortable_grid($name, $header, $content, $paging_options = array(), $query_vars = null, $form_actions = array(), $visibility_options = true, $sort_data = true, $grid_class = array(), $elementCount = 0)
 {
     $column = 0;
     $default_items_per_page = isset($paging_options['per_page']) ? $paging_options['per_page'] : 20;
     $table = new SortableTableFromArray($content, $column, $default_items_per_page, $name);
     $table->total_number_of_items = intval($elementCount);
     if (is_array($query_vars)) {
         $table->set_additional_parameters($query_vars);
     }
     return $table->display_simple_grid($visibility_options, $paging_options['hide_navigation'], $default_items_per_page, $sort_data, $grid_class);
 }