I have four textboxes. 3 of them are multiplied by each other to get the
answer in the fourth box. Sometimes there is not information for the first
three boxes so the fourth textbox must be inputted manually. I need to able
to automatically calculate when there is information and manually input when
there is none. I need some coding to be able to this. I also need to
disable the total box when calculating manually but enable it when entering
manually. Can anyone help?