TR_LOAN_POST_DATA - MOST URGENT

how to test this function module .

it consists of 2 - mandatory structures to be filled.

how do i test this - provid me some tips to test this function module.

i filled some values and executed - still it i thorows some error............( i already debugged but it takes us to so deep consists of many "FM" inside).

pls provide some tips - ASAP.