Problems in HR_infotype_Operations (Please Enter Assignment Status.)

Hi Experts ,

i have a problem in modifying employee details through portal .

scenario is like this, say particular employee Pernr 999 is opened in PA30

and i tried to modify the same Employee pernr 999 through portal

using the standard function module HR_infotype_Operations.

it return a error (Please Enter Assignment Status.),

when i try to lock the particular emploee pernr 999

the following error returned (personnel number(s) could not be locked

in my knowledge it is due to that particualr employee is locked in PA30 ,

can suggest any work around to solve the problem .?.

Thanks & regards

Renjith MP