  That lets you make
   a button operate only when the GPIO 7 button is being held down, or
   only when it's <b>not</b> being held down, or regardless of whether
   it's up or down.
</p>
<p>
   By default, buttons aren't sensitive at all to the shift bits.  If you
   want to create a button that ignores any shift buttons you've defined,
   you don't have to do anything at all, because that's the default.
</p>
<p>
   If you want to make a button operate <b>only when the GPIO 7 button is pressed</b> -
   in 