I haven't fully implemented this but I think I figured it out. Using Dan's world famous IOL technique and handy dandy JavaScript, I am going to add an "oninput" event to the input element and trigger the OnBF(this) that is normally triggererd when the element is blurred (or no longer selected, as happens when we click outside of the input field). This way, every time the user types a new character, the input element performs the same action as when we click away from it, thus updating the formula for the "Enter" button.
_EDIT:_ I did also have to add an "onkeypress" event handler to the text box to click the button as well because hitting the enter/return key was not registering as clicking the "Enter" button because it is a link element rather than a form submit.
