How to checks the concurrent request states/ Status

A PL/SQL procedure can check the status of a concurrent request by calling.

FND_CONCURENT.GET_REQUEST_STATUS
FND_CONCURRENT.WAIT_FOR_REQUEST

 FND_CONCURRENT.GET_REQUEST_STATUS :
-          This function returns the status of a concurrent request
-          If the request is already computed, it also returns the completion message.
-          This function returns both user friendly (translatable) phase and status values as well as developer phase and status vales that can drive program logic.

Syntax  Function FND_CONCURRENT.GET_REQUEST_STATUS
                   ( request_id in out number,
                   application in varchar2 default null,
                   program in varchar2 default null,
                   phase out varchar2,
                   status out varchar,
                   dev_phase out varchar2,
                   dev_status out varchar2,
                   message out varchar2) return BOOLEAN;

-          when application and program are specified, the request_id of the last request for the specified program should be returned to request_id.
-          Phase, and status values should be taken from

FND_LOOKUPS
dev_phase                                          dev_status
pending                                    normal, standby, scheduled, paused
running                                     normal, waiting, resuming, terminating.
Complete                                  normal, Error, warning, cancelled, terminated
Inactive                                     disabled, on-hold, No-manager, supended

FND_REQUEST.WAIT_FOR_REQUEST :
-          This function waits for request completion, then returns the request phase/status and completion message to the caller.
-          Goes to sleep between checks for request completion.

Syntax FND_CONCURRENT.WAIT_FOR_REQUEST
     ( request_id in number default null,
     interval in number default 60,
     max_wait in numbe default 0,
     phase out varchar2,
     status out varchar2,
dev_phase out varchar2,
dev_status out varchar2,
message out varchar2) return BOOLEN;

 FND_CONCURRENT.SET_COMPLETION_STATUS :
-          this function should be called from a concurrent program to set its completion states.
-          This function returns TRUE on success, other wise FALSE.
Syntax  function 
FND_CONCURRENT.SET_COMPLETION_STATUS
     ( status in varchar2,          message in varchar2) return BOOLEAN;
Normal status  warning message any message Error