Assigning a Value (Re-Explained)

In my previous post I think I explained my situation improperly, so let me try it again I have a multi-table database, I have a form that creates a new record for one table yet updates a record in another table. In the form if the person types in "yes" for the completed field, I need PHP to convert yes to a "1" else it will convert it to a "0" the table that uses the numbering system keeps track of the completed tasks. so this number will increase from time to time. Here is what I am looking at doing when a person enter in the word "yes" $addcompleted=$Row[total_completed]+$Array[completed_today] Then in the Update portion of the script have: ..... SET total_completed='$addcompleted' WHERE .......... any help and explanation would be greatly appreciated, I guess I just don't understand the How and Why of the function Thanks, jess