PO CHANGE OR NEW Indicator Field

Hi Gurus,
I want to know when new PO is created then, by which field or logic we can know that this is a new PO.
or when exsisting PO is changed then how to know that there has been a chage or it has been cancelled.
So I need that field or table from which i can know the this is a new or chage or cancelled PO.
I need to put this information in Outbound IDOC (ORDERS03) SEGMENT-E1EDK01, Field - ACTION.
Kindly let me know the logic for this.


Select all records from CDHDR with OBJECTCLAS = 'EINKBELEG' and OBJECTID = PO number.
If will select only 1 record with CHANGE_IND = 'I' than PO have been only created.
If will select several records (CHANGE_IND = 'I' or 'U') - PO have been modified or cancelled.