Android : Popup Bar In Mail Application

In the Android Mail application, when you click the checkbox next to an inbox message, a little bar with buttons (mark unread, delete, star) appears at the bottom of the screen. I'd like to do something similar, but I don't think I'm going about it the right way. What I've done is add a LinearLayout below my ListView and marked the visibility GONE. When a user clicks a checkbox next to a list item, the LinearLayout's visibility is marked VISIBLE. Unfortunately, checkboxes stop working. By this I mean the skin on the checkbox does not change from unchecked to checked; and I can't figure out why. (...or rather, this is the way I HAD it. I removed it once I couldn't fix it and, since trying to add it again, it just crashes, but I digress)