Microsoft Small Basic

Program Listing: JLK064
maxNumber = 1000
sum = 0

For i = 1 To maxNumber - 1 ' below maxNumber
If Math.Remainder(i, 3) = 0 Or Math.Remainder(i, 5) = 0 Then
sum = sum + i
EndIf
EndFor

TextWindow.WriteLine("Sum = " + sum)