The variables have a scope. If they are declared in a procedure (rather than
in a module before the procedure declaration for example) then they are
created on entry to the procedure and "destroyed" on exit. So not only do
they not have a value outside of the context of the running procedure, but
they actually don't exist. i.e have no memory allocated to them.
If the hover does not work you can always open the immediate window (Ctrl G)
and print the variable  value with *? variable name. *Not as convenient as
the hover option, but viable. Of course there is also the option to set a
watch on a variable and to see the changing value in the watch window.
Hope this helps some.