RegisterScript(<-name)
Registers the current script instance with a name. This name can be used with GetRegisteredScriptVar. If the same name is used as another script instance, this call will deregister the other script instance and replace it with the new one. A script on a unit is a unique instance. Each global script instance is also unique.
Note that registering a script is NOT persistent. It will not be saved in a save game file. You must reregister a script.
RegisterScript("MyScript")