How to Hover over and click on an invisible element using selenium webdriver?

Question

There is an invisible element on my HTML page which becomes visible when a mouse hover is done on the element. What I Have to do is

1. Hover over the element
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Answer 1

Actions builder = new Actions(driver);
builder.MoveToElement(menu).MoveToElement(submenu).Click().Perform();

It works under Chrome, but doesn't work in FF