Joining a random Network Room in an online game

Hey, I'm trying to get it to where instead of picking which room you join in my online game, you just press a button and it picks a random one for you. Any ideas how I could do this?

EDIT: I figured it out, here's my code if anyone's interested: JoinServer(hostList[Mathf.Round(Random.Range(0, hostList.Length))]);

Another EDIT: Typical unity, my code above worked for 10 mins, and then stops working. Any ideas why?