Preventing SQL injection

//prevent injection
    function qry($query) {
// Connect to database
      $this->dbconnect();

// get function arguments.
      $args  = func_get_args();

// Get first argument.
      $query = array_shift($args);


      $query = str_replace("?", "%s", $query);
      $args  = array_map('mysql_real_escape_string', $args);
      array_unshift($args,$query);
      $query = call_user_func_array('sprintf',$args);
      $result = mysql_query($query) or die(mysql_error());
          if($result){
            return $result;
          }else{
             $error = "Error";
             return $result;
          }
    }