Hi Diwakar,
I want you to use the FLUSH method before your computation. That is what is I mentioned in my earlier reply, to use immediately after you pick the data into your internal table after the user selects the number of records.
1. ALV Event handling
1.1. Here, check if the internal table has got the selected values and if they are in place, use FLUSH to clear the memory (Don't check for Initial of Internal table)
2. Use same FM
3. User click checkbox will Trigger PAI
4. Do some computation.
After you do the computation and reach the PBO, still the memory will hold the same values of ITEM1. So before you enter into this PBO layer you should clear those values.
Please do this in the debugging mode and paste those screen shots if possible otherwise you can send them to my mail Id and I will check the same from my end.
Thank You!
Syed.