Actionscript :: Creating Drag Bar Purely?

I've been having trouble creating a mechanism to allow the user to select a span of time from a timeline. Basically i want them to be able to click and drag horizontally, and retrieve the start and end positions of that event.

I especially need to include the case where the event goes off the edge of the screen (even if the end position is snapped to the edge of the screen that's fine).

While doing all of this, I want to be able to draw a box that goes from the start of the event to the current position of the mouse, so that it's obvious which area if being selected.