plzzzzzzzzzzzzzzzz help.

Currently the goods receipt confirmation is being performed in a non -sap system . A new interface to SAP is required when the receiving location physically receives the material in their non-sap system .The goods receipt information will flow back into SAP. The inbound interface will update the SAP Inbound Delivery Goods Receipt (material, quantity, batch, date) and post the goods receipts. In the case of a stock transfer order the stock will be transferred from in-transit stock to stock on hand.

I am very new to ABAP . can anyone give me an idea about that ?