It is more than likely your internet connection/PC performance or a very old and unstable web browser that is at fault.

1. Click on the date that you are looking at.
2. Then click on a time slot.
3. A dialog will popup so you can tweet it if need be, and add any additional notes.
4. Once clicking OK a confirmation dialog will show. Clicking that will Book your appointment.

If you wish to edit or delete the appointment, just click on it, but once you have exited the program, you will no longer be able to do this.

Unfortunately it is impossible at the moment, for you to change a booking that was entered in a previous session.
You should have received a confirmation email regarding your previous booking, reply to that email with a new date and we should be able to re arrange your appointment

Tell you what, have a month in my shoes, seriously I mean it, Follow me around for a week, and then take over my life for 4 weeks, then you might have an idea that 24 hrs a day is not enough for all the stuff I have to do.

Seriously I have no Idea???!!!