Thanks for the confirmation William.
Typing is a good suggestion, but I need the username (teacher) to be a sort-order and search field, so it can't really afford to have inconsistency or mistakes. The next best thing is to make a menu of names to choose from, but I was trying to make entering homework as simple and quick as possible for them.
I think either the students will quickly learn that clicking the name will give them an error, so they will stop clicking it. It's ugly, but not a big deal.
But maybe later on I can learn to edit and control the profiles enough that they can be useful and unobtrusive - that would be ideal really.
Thanks.