Forms :: Stop Tab From Starting New Record In Form

I have created some control buttons using the built in functions of Access2007 and then using the script supplied here modified the control.

So far the controls can add new record, save record, exit form, open next form and close existing form, open previous form and close existing form.

My next question is when the user reaches the end of the form fields how do I stop the form from automatically starting a new record?

For example, I use the TAB key to move from field to field and when I tab out of the last field the form goes straight to the next empty record.

I want this to be a deliberate action performed by clicking the Add New Record button and not an accident of a key press.

The other thing is, how do I get the form to open with blank/empty fields and not at the first populated record?
Some of the data is updated frequently so the records need to be able to be edited but I need to prevent accidental editing of the existing records.