How to get parameter output in SQL Server Store Procedure

[eluser]zawaruddin[/eluser]
I've a procedure in SQL Server 2008

Code:

CREATE PROCEDURE dbo.testing
    @parm varchar(10),
    @parmOUT varchar(30) OUTPUT
AS
BEGIN
   SELECT @parmOUT = 'parm 1 ' + @parm
END

and i have a query to access this procedure

Code:

$param1 = 'test';
$param2 = '1';
$this->db->query("dbo.testing ?,  ?", array($param1, $param2));

i've execute the procedure, but i can't retrieve 2nd parameter value.

Anyone have idea to get this 2nd parameter value??

thanks