throwerror int_expr
throwerror ( int_expr )

Cause a runtime error to occour. These errors may be trapped with the Onerror statement.

onerror errortrap
print "before error"
throwerror 99
print "after error"
end

errortrap:
print "error " + lasterror + " happened"
return

will display

before error
error 99 happened
after error