Newbie Question, Basic Table Automating Entries

Hi all, new member with a newbie question. I have just started working with Access, so pardon if this question is unclear or pitifully basic. We have a basic database comprised of client names, amounts paid to-date and balance due. It also has a field named date last paid, so here is the question. When you enter or change the amount in paid to-date, can you automatically have the date of the change (ie. Todays Date) entered in the "Date last paid" field.

Thanks all for the help in advance.

Chris