problem with sap inbox message

Hi guys,

I am submitting a prog Z2 to a background job in a main prog Z1.In the prog Z1 i used job_open, submit Z2, job_close function modules for background processing.When the prog Z2 is executed it sholud send a sap inbox message to the triggering user.The inbox message is working fine and coming to the triggering user also, but the message is coming twice.

When i debugged the main prog Z1, after the statement submit Z2 is executed it is sending a inbox message,then after the function module job_close is executed again another inbox message is coming.So finally i m getting 2 inbox messages at once in the output.

Can anyone please tell me the problem and where I m going wrong?

Thank you.