If you launch an application after creating a global variable in HyperCard,
when you return to HyperCard from the application, the global variable is
no longer defined. You will be running under the Finder.
If you want the value of a HyperCard global variable to be saved across a
launch, you will need to use the "suspend" and "resume" messages, save the
value of the variable somewhere, and then restore it.
(NOTE: If you are running HyperCard under MultiFinder, you will not have
this problem since HyperCard stays active when you open another
application.)