update table with sub form

[dede]

i have a form in access project that contains subform, example
my sub form value:
name point
A 5
B 8
C 5

I want to update table point value with subform above, by clik update
buttom in form .example:
point table:
name point
A 2
B 1
C 0
D 1
E 2
.... ..
after update
name point
A 7
B 9
C 5
D 1
E 2

i try to use store procedure but i can't solved.
can any one help??
thx before