Hiding menu for certain loggedin user roles

I was able to hide a menu item for non-logged in users, but can’t understand how to hide for certain user roles. Using the example, I put in the visibility box for the Event|Create sub-menu item:

in_array(‘Editor’, $GLOBALS[‘current_user’]->roles)

This results in an error saying the 2nd arg of array is null. Only thing I can think of is there are no Editors currently logged in.

Are there some examples somewhere?

The page I need help with: [log in to see the link]