How to unreserve order using API?

Dear all,
We need to do unreserve order by using API. I call OE_ORDER_PUB.process_order by the following script :

CREATE OR REPLACE PROCEDURE APPS.UNRESERVE_ORDER AS
BEGIN
   DECLARE
     l_header_rec OE_ORDER_PUB.Header_Rec_Type;
     l_line_tbl OE_ORDER_PUB.Line_Tbl_Type;
     l_action_request_tbl OE_ORDER_PUB.Request_Tbl_Type;
     l_header_adj_tbl OE_ORDER_PUB.Header_Adj_Tbl_Type;
     l_line_adj_tbl OE_ORDER_PUB.line_adj_tbl_Type;
     l_header_scr_tbl OE_ORDER_PUB.Header_Scredit_Tbl_Type;
     l_line_scredit_tbl OE_ORDER_PUB.Line_Scredit_Tbl_Type;