Is JavaScript single threaded? If not, how do I get synchronized access to shared data?

Question

I have a web page with DIVs with a mouseover handler that is intended to show a pop-up information bubble. I don\'t want more than one info bubble

Answer 1

Yes, Javascript is single-threaded. Even with browsers like Google Chrome, there is one thread per tab.

Without knowing how you are trying to cancel one pop-up from another, it's hard to say what is the cause of your problem.

If your DIVs are nested within one another, you may have an event propagation issue.