It should be working then.
If username is defined and they are an editor then all the global does is count from the Editors table where the username matches what you passed in, so as long as they exist in the Editors table then it should be returning 1 aka "true" and should then load the hyperlink :(
If username is defined and they are an editor then all the global does is count from the Editors table where the username matches what you passed in, so as long as they exist in the Editors table then it should be returning 1 aka "true" and should then load the hyperlink :(