Forcing a script to exit early?

[TerranAce007]

If a script is still running, but something in my mission happens that exceutes a new script, how can I make the first script stop where it is and exit?

Would this be accomplished by a trigger in the mission, or within one of the scripts?

Also, can I define a variable in a trigger:

condition: Not alive person;
Activation: Dead = True;

Then call the variable in a script with the ? command to check whether Dead is true or false?