Unable to get the main partner from BT order

Hi All,

Facing the below issue.,..

How to Get the Main Partner from the BTOrder.

I have used the below code ..

but its not giving me the main Partner..

Changed the Relationship to BTPartnerAll and then i got the employee responisbility..

Extracted Employee responsible but not main partner..

Kindly help

      TRY.

          lr_adminh =  lr_order->get_related_entity( iv_relation_name =   'BTOrderHeader' ).

        CATCH cx_crm_genil_model_error.    " Error when Accessing Object Model

      ENDTRY.

   TRY.

            lr_partner = lr_adminh->get_related_entity( iv_relation_name = 'BTHeaderPartnerSet' ).

          CATCH cx_crm_genil_model_error.    " Error when Accessing Object Model

        ENDTRY.

          TRY.

              coll = lr_partner->get_related_entities(

                  iv_relation_name = 'BTPartner_PFT_0001_MAIN' "'BTPartnerAll'

              ).

            CATCH cx_crm_genil_model_error.    " Error when Accessing Object Model

          ENDTRY.

          current = coll->get_current( ).

          IF current IS BOUND.

            current->get_property_as_string(

              EXPORTING

                iv_attr_name      =  'PARTNER_NO'   " Component Name

*                  iv_use_iso_format = ABAP_FALSE

              RECEIVING

                rv_result         = lv_partner

            ).