Urgent..Please help!

Hi Friends,

I am not very gud in MS Access.Please check out the below example and help me.
Product_name Price
P1 $20
P2 $10
P3 $5.......

Mon Week_no Prod_name No_of items
1 1 P1 4
1 4 P1 10
2 4 P1 20
3 4 P1 10
2 3 P2 50........

Assume that Price of P1 changed to $40 in Feb.
Now I want to calculate amount earned by selling P1 from Jan to March.
Remember (For Jan the rate will be $20 and from Feb to March it will be $40)
If I calculate manually it will be - 4*$20 + 10*$20 + 20*$40 + 10*$40

But How do I do it using a query or code??

You cannot or atleast not with the data given, you would need to redesign your tables to allow for a "price end date" in the first table.

Edit: Please just ask questions once... http://www.access-programmers.co.uk/forums/showthread.php?t=123475