Please help me with SQL in MS access

I have a table named "Cost" as the following in access 2003:
Date Name Cost
1/3/07 Jack 90
1/24/07 Jack 30
1/6/07 Tom 98
2/10/07 Alice 100
3/30/07 Jack 100
.......
I would like ask user to input date as"m/d/yy" first, then ask user input "Name". I need a code to show me the result of Month to date total of a person i.e. if user input "1/31/07" and name as "Jack", the result should be 120. :) I also need a code to show me Year to date total of a person i.e. if user input "4/1/07" name as "Jack" The result should be 220. Thanks a million!