Dim btnnum(8) as button
for j= 0 to 8
btnnum(j).Initialize("btnum")
btnnum(j).tag= j
panel (or activity..) addview(btnum(j),...)
next
sub btnum_Click
dim swap as string
Dim btn AsButton = Sender
Dim index as Int = btn.Tag
If btnnum(Index + 1).BackColor = colors.White Then
swap =btnnum(Index).Caption
btnnum(Index).Caption = ""
btnnum(Index).BackColor = colors.White
btnnum(Index + 1).Caption = swap
btnnum(Index + 1).BackColor = colors.Blue
end if