Joindin 441: Redirecting the I'm attending button

Would someone be able to review my changes to Controller/Event.php, I'm not convinced that the way I'm doing the redirecting is the best way. If anyone can suggest something better that would be great.

Protip: is_numeric does not only check if all elements in $page are digits but also supports scientific notation (1e12). If you really want to check for digits you are better of using [filter_var](www.php.net//manual/en/function.filter-var.php) with the FILTER_VALIDATE_INT filter.

> This might or might not be something you would want to change; just trying to be helpful with some extra info :)