Unfortunately there’s no standard event for knowing when a select box is closed or open, so your code is going to be pretty hairy with accommodations for different browsers. That said, I think it can be done, and I’ve gotten something working for you in Firefox using the mouseup event:
In Firefox (and I’m assuming Chrome), you’re going to need to track the state of that select pretty carefully. When an escape key is pressed or blur event occurs, you need to update the state to identify it as closed. I haven’t implemented that in my demo, and you can see what happens if you hit escape instead of clicking off the select.
Things were easier in Safari, where a mousedown event on the select signifies opening the select, and any close of the select is signified by a click event.
If you find a browser where none of these events fire, you can try one additional trick. Because form widgets like select and textarea are often rendered by the OS and not inside the browser it’s possible that you could interact with them and certain messages might not get down to the browser’s event handler. If you were to position a transparent textarea covering the screen at a lower z-index when the select box is open, you might be able to use it to track that close click. It may be able to capture events that a browser DOM element may miss.
Update:
Chrome sees a mousedown on the select when it opens and a mouseup on the document when the page is clicked with a select open. Here’s a version that works with Chrome:
Again, you’ll need to do some browser detection to handle the right behavior in each one. One catch with Chrome, in particular, is that no event is fired when you click on the select a second time to close it. You can detect the page click, however.
Quick Summary:
Chrome/Safari: select.mousedown on open, document.mouseup on close
Firefox: select.click on open, document.mouseup on close
IE8/IE7: select.click on open, document.mouseup on close
There are an awful lot of edge cases for other events that will signify a close (escape keypress, blur, etc.), but these are the minimum to handle the scenario where a user clicks the select box and then clicks off into the document area.
Hope this helps!