How to see refcursor result/output in Oracle SQL Developer?

Possible Duplicate:
Best way/tool to get the results from an oracle package procedure
Oracle SQL Developer: Show REFCURSOR Results in Grid?

I am new to Oracle SQL Developer. I am using Oracle SQL Developer Version 3.0. I was trying to test my SP using the following query.

DECLARE
  type output_cursor is ref cursor;
  P_CURSOR output_cursor;
BEGIN
  P_CURSOR := NULL;
  myPackage.mySPTest (  P_NOTIFICATION_ID => 1975357,P_CURSOR => P_CURSOR) ;
END;

When I ran the above query in my Oracle SQL Developer, I am getting a message 'anonymus block completed' and its not showing any result.

Can anyone help me, how to see the result.

.