stop

Stops the procedure that is running. Stop can only be used in a procedure. See stopall and stopme.

Example: 

The second line of this procedure is called a stop rule.

to countup :number 
if :number > 100 [stop] 
print :number
countup :number + 5 
end

Try: 

text1,
countup 0

Other examples of stop rules.

if colorunder = 15 [stop]
t1, if (distance "t2) > 100 [stop]
if slider1 < 1 [stop]
if empty? answer [stop]
if empty? text1 [stop]