How to show output parameter result when calling procedure from forms personalization

Dear All

I am calling a procedure from forms personalization. It is running successfully but I want to show Success or Failure status in an output parameter which should be popup in screen. I am using following syntax to call procedure.

='declare

v_output BOOLEAN;

XX_OUTPUT VARCHAR2(100);

begin

XX_GENERATE_CRN.xxrcl_amount('${item.ORDERS_SUMMARY.HEADER_ID.value}',XX_OUTPUT);

END'

Now I want to know how to popup output result in XX_OUPUT parameter.