adding values to tables using checkboxes

[teh.redworm]

Hi, I'll get right to the point.
I have a table called interests with atributes InterestID, InterestName
and InterestDescription. The administrator stores a few interests in
here, but it won't be changed by users.
Next I have a table called userinterests with atributes UserID and
InterestID.

I want to create a form where I can check various checkboxes and it'll
store the UserID and the InterestID of that checkbox in my
userinterests table.

Thanks in forward.