Actually two types of modes are there.One is Global Gui and
other is GuI map Per Test mode.
   In Global one Gui file maintained for several
scripts.It's not included with the script.You have to
explicitly store the GUI map file and you 've to explicitly
Load the Gui using GUI_load() statements.
   Advantage of Global GUI is if the application properties
changes then you've to change the one GUI onlu..
Further discussion welecome..

This is the default mode for saving GUI Map file.

It saves all the objects for multiple tests into one place, 
so it saves the memory.
Say i have an application with 100 objects and test1 used 
80 objects and test2 used 90 objects and test3 uses 70 
objects, at max the total size of the Global GUI Map file 
is 100. If u use GUI Map File Per Test mode then the total 
size is 80+90+70.
We need to explicitly save this Global GUI Map File. We 
need not explicitly load this file, because it saves all 
objects in the temporary GUI Map file.

If any object properties changes, then we need to change in 
one place.

In Short the Global GUI map is nothing but a store house of 
all properties of an Application under test globally,It has 
all the properties stored concerned with all the objects 
that has been recorded.

This Global is used here as these stored properties can 
accessed by any user ,from any other module of the 
application.