Expanding and Contracting Circle

                                    ` This code was downloaded from The Game Creators
                                    ` It is reproduced here with full permission
                                    ` http://www.thegamecreators.com
                                    
                                    
set display mode 640,480,32
set text font "terminal",1
set text size 12

cls
hide mouse
randomize timer()

do

for i=1 to 75
   circle 320,240,i
   sleep 1
   cls
next i

for i=75 to 1 step -1
   circle 320,240,i
   sleep 1
   cls
next i

loop

wait key