IntControl (79, p1, p2, p3, 0)
Causes a user-defined error.
IntControl 79 has been superceded with the function ErrorEvent.
p1 = severity, which can be one of the following:
-1 minor error
-2 moderate error
-3 severe error
p2 = error code, which must be a number between 7000 and 7999.
p3 = error message, which is a string describing the error.
Returns 1.