funzione con query ed limit

[rocco.mod]

salve ragazzi volevo chiedervi , io ho una query che estraggo i dati dal database, però non riesco ad estrarre i dati.
questa e la query

    $num_results = $result ; //this value should arrive from some database query, like "select count(id) from table_you_want_to_page" 
    //echo $num_results ;
    $per_page = 1; //number of results to be shown per page
    $query_string = "class.pager.example.php?"; // current file.. 
    $pager = new pager($num_results, $per_page, $query_string); //building a pager
    $sql ="SELECT * FROM tech order by staffid asc limit ".$pager->num_results.",".$pager->per_page."";
    $query =  mysql_query($sql); 

e la funzione dentro la classe:

        function pager($num_results, $per_page = 10, $query_string = '', $page_id = "page") {
            $this->page = $_REQUEST[$page_id] ? $_REQUEST[$page_id] : 1;
            $this->page_identifier = $page_id;
            $this->per_page = $per_page;
            $this->num_results = $num_results;
            $this->query_string = $query_string;
            $this->page_list_size = @ceil( $num_results / $per_page );
        }