PO Idocs

Hi,

When i create a PO with some 3 items it is savinf successfully and an idoc is triggered, when i look into an idoc 3 line items are appearing with action 001. After that when i change the second line item and click save then a new idoc is triggered now when i look into an idoc again the action is 001 even if i delete an item even then also action is 001 in idoc. As per my knowledge the action 001 indicates item added, 002 indicated item changed, 003 indicated item cancelled and 004 indicated item not changed. But what ever the action i do in PO still the action field in idoc remains same.

Kindly suggest is there any settings to be done at PO side when creating or changing.

Regards,

vinit