table EKBE-Sum value of all movements

Hi,

I am developing one report for OPEN PO list.so I am using EKBE table to get all  records value qty and comparing with EKPO-MENGE table,.while doing suming all of movements of (101,105,122,103) qty, I need to  sum up for each PO with individual material qty,so that I can compare with EKPO-MENGE with each mateial.I donot know how to sum up? I tried with EBELN and MATNR with at  statement.But I am NOT getting right correct sum of qty for each mateial with PO.

For this issue,can some throw light on this,please?

with Regards,

Jaheer