10 rem Leap year
20 for i% = 1 to 5
30   read year%
40   print year%;"is ";
50   if isleapyear(year%) = 0 then print "not "; else print "";
60   print "a leap year."
70 next i%
80 end

200 data 1900,1994,1996,1997,2000

400 sub isleapyear(y%)
410   isleapyear = ((y% mod 4 = 0) and (y% mod 100 <> 0)) or (y% mod 400 = 0)
420 end sub