I need help with a formula for my inventory master list.

I have several worksheets, the one I need a total from is the Inventory in
Worksheet. Everytime we purchase an item and enter it into my Inventory In
sheet I want it to do a total of how many of that item we have purchased all
year in my Inventory Report sheet.

Lookup quantities of an item in another worksheet to give a total in another.

Sorry if my wording is erratic, I have hard time explaining but know what I
need. Some sort of eg;


Inventory In;
Item Qty In
149 10
160 10
155 10
149 30
155 20


Inventory Report;
Item Totals
149 40
160 10
155 30


Thanks;