ME2A not showing all values

Hi Guru's

I am implementing a process where in we are using following steps for tracing material which is in transit.

1. Make PO

2. Go to change Po and use confirmation tab in PO and use Order acknowledgement and use 'LA' for inbound delivery.

3. Go to VL31N and do inbound delivery.

4.Then we are checking the report ME2A, but it is not showing the purchase order against which we have done inbound delivery.

Can you tell the logic of this report how it works. I want to give this report to my end user who are chasing for the material. We want to utilize this report for trace material.

Regards

Chetandeep