Inventory Calculation

[ser01]

I am new to access and have been desperately trying to solve a problem i am having with a database that i am building. And no success so far. Hopefully someone can help me.
What i am trying to do is calculate the inventory. The calculation needs to be based on existing inventory numbers imported from a different program, and orders that would be entered in the database that i am building. So when a new order is being placed, next to the field where the quantity for the order would be entered, the calculated inventory would be displayed. To do the calculations all the previously entered orders for individual items would need to be sumarised, then substracted from the existing inventory. The only way i was able to achieve that is by using a TOTALED query and using some functions for the calculations. It all works as far as the calculation. The problme is that the the whole query becomes unupdatable, so the quantity can not be entered any more. I imagine this is because of the query being totaled? Can any one make any suggestions for how the above can be acomplished?
Thank you in advance!

[maximus]

DSum Function is what you might want to look at it for your particular problem. I had replied to a thread which explains the scope of the function take a look at it.

follow the Link:
https://www.accessforums.net/reports...dsum-4949.html