Bruce:

You already received a couple of good answers. My point however is that you should assign other keys (CTRL+HOME, CTRL+END) to the proposed options.

HOME and END are assigned behaviors that are very useful (moving the insertion pointer to the beginning and end of the textbox) and I know my users would not appreciate it if I overrode useful functionality with something else.

There is nothing wrong with providing the extra functionality you propose. However you should be careful not to remove any existing functionality.

Daniel