to trace
cs 
new setw 10 stamprect  10 10 make g1 pid
new setw 10 stamprect  10 10 make g2 pid
new setw 10 stamprect  10 10 make g3 pid
new 
setw 1
label "boo
wait 1 
seth towards mouse 
make cx (mousex-xcor)*159/160  
make cy (mousey-ycor)*159/160 
setxy mousex-cx mousey-cy 
psxy g1 xcor-cx/4 ycor-cy/4
psxy g2 xcor-cx/3 ycor-cy/3
psxy g3 xcor-cx/2 ycor-cy/2

go "boo
end
