getAttribute is not a function for nav elements with margins

[clethrill]

I am getting the error TypeError: current.getAttribute is not a function. I have tracked it down to the onMouseOver function in SideNav.js. It seems if a nav element has any margin and you hover your mouse over the area with a margin e.target in the onMouseOver function is set as the aside element goes throw the while loop all the way up to the html document level and then fails.