Reports problem:I am submitted this code but reports not run.

[123oli]

PROCEDURE invoice IS
repid REPORT_OBJECT;
v_rep varchar2(1000);
rep_status varchar2(20);
PL_ID PARAMLIST;
pr_nm varchar2(20):='PNM';
v_rptserver varchar2(10):='oliur';----1
--rwserver server=oliur EXECUTE IT ON RUN
v_host varchar2(20):='localhost';---2

BEGIN
PL_ID:=GET_PARAMETER_LIST(pr_nm);
IF ID_NULL(PL_ID)=FALSE THEN
DESTROY_PARAMETER_LIST(PL_ID);
PL_ID:=CREATE_PARAMETER_LIST(pr_nm);
IF ID_NULL(PL_ID) THEN
MESSAGE('ERROR CREATING PARAMETER LIST '||pr_nm);
RAISE FORM_TRIGGER_FAILURE;
END IF;
ELSE
PL_ID:=CREATE_PARAMETER_LIST(pr_nm);
end if;
--add parameter with separate statement for each parameter
--ADD_PARAMETER(PL_ID, 'P_BDT',TEXT_PARAMETER,:BAZAREXP.BAZARDT); ----3
-- ADD_PARAMETER(PL_ID, 'PSAL',TEXT_PARAMETER,:SALARY);
repid := find_report_object('REPORT77');---4

SET_REPORT_OBJECT_PROPERTY(repid,REPORT_EXECUTION_ MODE,BATCH);
SET_REPORT_OBJECT_PROPERTY(repid,REPORT_COMM_MODE, SYNCHRONOUS);
SET_REPORT_OBJECT_PROPERTY(repid,REPORT_DESTYPE,CA CHE);
SET_REPORT_OBJECT_PROPERTY(repid,REPORT_DESFORMAT, 'PDF'); --pdf/html
SET_REPORT_OBJECT_PROPERTY(repid,REPORT_SERVER,v_r ptserver);
v_rep := RUN_REPORT_OBJECT(repid,PL_ID);
rep_status := REPORT_OBJECT_STATUS(v_rep);
IF rep_status = 'FINISHED' THEN
/*Display report in the browser */
WEB.SHOW_DOCUMENT('http://'||v_host||':8889/reports/rwservlet/getjobid' ||
substr(v_rep,instr(v_rep,'_',-1)+1)||'?'||'server='||v_rptserver,'_blank');
ELSE
MESSAGE('ERROR WHEN RUNNING REPORT');
END IF;
END;

I am submitted this code but reports not run.ORACLE 10g