1) If you have a Google Plus account, go to your home page.
2) On the right side, there's a list of "Add to Circle" buttons that you can hover over.
3) Notice that when you hover over one of the Add to Circle dropdown (if you have enough circles to have scrolling in the dropdown) the page scrolling feature is disabled. Only scrolling vertically in the dropdown is allowed.
How is this done with javascript?
I can scroll in here (the scroll bar on the right), but can't scroll on the page body while this is dropped down.
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