Robert O'Toole6,336 Points
just wanted to let everyone know about .classList.add(li) classList.remove() and .classList.toggle(li)
its a cool alternative way to change or add class lists. the toggle feature is especially helpful to know for click events like this.
Steven Parker203,116 Points
These are not only handy, but they preserve any other classes that might be set on the element. Simply assigning "className" (as is done in some of the examples) would wipe them out.