Availability Check - Messages

Hi, Consider this Scenario.

I have 2 Materials (M1 & M2) maintained in Same Storage location (e.g. 0005) & Plant (e.g.1000). There is no stock for both these items (MMBE).

Now, I created sales order for these items. Availability check is carried out (Checking grp 02 & rule A) and qty is confirmed based on RLT I think. ATP is Minus.

Now, while creating delivery for Material M1 i am getting an error message as soon as I enter the storage loc 0005 " only x unit of Material M1available". Whereas for material M2 I am not getting the error message though I dont have stock for this item too.

The requirement is Client wants this message to appear when creating a delivery for an item if there is no stock.

Additional info:- If I turn Off Availability check at the delivery, I am not getting this message.

Is this activated at Availability check or at Storage location or where ??

Kindly help me on this issue.

Thank you

Mohamed Imran R