Try removing the eels from your hovercraft.
For help on that, there's a link in my signature.

"Huh? What?" you say... "What does that have to do with your question?" Everything. Specifically, the lack of details. How are you creating this dropdown menu? How is it invoked? What does the code look like? It's not going to do anyone any good to post an answer only to find out that either a) you already tried it and it didn't work (in which case, specify what happened when you did) or b) isjn't compatible with what ever you're using (what if you using something like React or JQuery, and someone gives a perfectly good answer but wrecks the rest of things?)

So read the link, and come back with some more details.

-tg