Server Utilities :: DBMS-DATAPUMP Import Error?

have a requirement to load .dmp files into existing staging tables and there is package to load the ODS tables from staging.So,I thought of using DBMS_Datapump utility to import the data from .DMP files to the Tables and this need be automated.

--Create Directory
CREATE
OR REPLACE DIRECTORY test_dir AS 'C:Test'

--grant Access to the User
GRANT READ, WRITE ON DIRECTORY test_dir TO scott;

--Script to import
DECLARE
l_dp_handle1 NUMBER;
BEGIN
l_dp_handle1 := dbms_datapump.OPEN(operation => 'IMPORT',

[code]...

Errors

ERROR at line 1:
ORA-31634: job already exists
ORA-06512: at "SYS.DBMS_SYS_ERROR", line 79
ORA-06512: at "SYS.DBMS_DATAPUMP", line 938
ORA-06512: at "SYS.DBMS_DATAPUMP", line 4590
ORA-06512: at line 4