How to debug a background job

At times you might find yourself in a situation to debug background jobs.
Is it possible in SAP?? Yes it is ...

There are two ways to achieve the same.

1) Goto sm37 (Job overview ). Select the job you want to debug , enter JDBG in the OKCODE.
This can be used to debug any process.

2) Code an infinite loop in your program at the point where you want to debug.

ex

do
if i=1
exit
endif
enddo.

Start the program.
Goto sm50 ( Process overview ). The process appears in the running state and then goes to hanging state.
click on the process.
Goto Program/mode -> program -> debugging.

Change the value of i at runtime in the debugger.