fetching price in the LPO

hi
i have created two sheets..
sheet # 1 contains the list of products with three different prices for different packings
sheet # 2 contains the purchase order

i want to enter product name in the purchase order along with the item and packing and want the excel to fetch the appropriate price of the product from the sheet#1 and fill the price field

sorry if somebody cannot understand my wordings
if will be very thankful if someone could get my point and help me solving the problem

There are many ways to do it but I would do it like this.
Hope this helps.

thanks a lot for reply
it certainly helped a lot but if you don't mind explaining this thing
i mean i want to understand the logic of the formulas used to do this thing...
thanks in advance