Finds a global variable with name s1 and deletes it from the global heap. Global variables can be accessed by any script on the map.

# In one script:
42 ->*myGlobalVariable
# In any script on the same map after that point:
"myGlobalVariable" --!*
-?*myGlobalVariable if
    "myGlobalVariable exists."
else
    "myGlobalVariable does not exist."
endif
trace
# Puts "myGlobalVariable does not exist." in the debug window.