break -- breaks out of a switch statement or a loop
break transfers control immediately outside the enclosing loop or switch statement. This is the preferred way of leaving a such a statement (rather than goto, which is still possible in most cases).
for a=1 to 10
case 2:case 3:print "Hi"
This example prints nothing at all, because each of the loops (and the switch-statement) does an immediate break (before it could print any "Hi").
for, while, repeat, switch