If you're making more complex missions, you can create
each part of your mission as it's own mission.
Then you can test each part by it's own.
Once you recon all works fine, the only thing you need to
do is: load up your main mission (or the first part), and hit
the "merge" button. With the merge function, you can load
the other parts into the one, already loaded.
Before merging it, just get sure you remove unnecessary
triggers or player's from the other parts.
Also remember that scripts won't be copied from one mission
folder into another by using merge (or save with changing to
a new name). So take care, you copy your scripts manually
in windows from folder to folder.
Summary: merge let's you make "one" out of "more".
~S~ CD