global variable not part of namespace

[Scubastooge]

So the issue is ive declared a variable in one file and called it in another like so:

File1.cpp:
classobject *var1;

File2.cpp
::var1->Dofunction();


This returns:

'var1' : is not a member of '`global namespace''


I'm still a little new to this so it might just be the syntax here.

Thanks in advance