Your menu links should just look like:
?Camp_Activities_Menu=3
In the one we worked on you were using the same page for multiple menus, so we had two parameters passed and some code on the top of the page to interpret it. In this example you only have one menu and don't have the code on top of the page, so you could either get and add the associated code, or update the link url as I've suggested to skip that step.