Simple logic

Dear folks

Although I have reasonable experience I have been unable to solve this "simple" problem, must be my age?

I thought perhaps you would help me solving a "simple" logic problem in Basic.
It is.....

1. A switch is open
2. The switch closes
3. Log the event
4. Go back to start
5. Is the switch open?
6. If so watch it until it closes again
7. Log the event...etc etc

Problem I can't solve is to disregard switch closed after first time until it has opened and closed again.

I want to monitor the number of times the switch has closed, opened and closed again.

At the moment as I cycle round it logs the switch closure every time, even though it has only been closed once.

Hope you can help with a bit of code

Rgds

Mike Denton