Send variables to different pages

[CXJ]

When I call the function setRedirect I currently have it set to the logout URL.

During the process, the variable containing my error message I want displayed to describe the reason they were logged out get's losts and I can't recover it. If I try to make the variable global or $GLOBALS it messes up the site and leaves users at blank pages.

Does anyone know a method I can use to store a variable then after I'm redirected to the loguout url, then back to the login page, call this variable to display a message to my users?

[CXJ]

No one knows how to store a variable that can be access across 2 pages?

It seems like the only questions getting answered are trivial issues regarding not knowing how to configure preinstalled plugins. I didn't think this question was that hard for these forums.