Structure TileStructure
        Dim FlagIndex As Integer
        Dim Flipped As Boolean
        Dim Matched As Boolean
        Dim TileRef As PictureBox
        Public Sub Reset()
            FlagIndex = -1
            Flipped = False
            Matched = False
        End Sub
    End Structure
    Dim Tile(16) As TileStructure
    Const UNASSIGNED = -1
    Const EARTH = 8
    Dim iLastFlipped As Integer
    Dim iNumFlipped As Integer

    Private Sub btnExit_Click(sender As System.Object, e As System.EventArgs) Handles btnExit.Click
        Me.Close()
    End Sub

    Private Sub btnStart_Click(sender As System.Object, e As System.EventArgs) Handles btnStart.Click
        Dim i, iPos, iFlag As Integer
        Dim iIndex(16), iIndexLimit As Integer
        For i = 0 To 15
            Tile(i).TileRef.Image = ImageList1.Images(EARTH)
            Tile(i).Reset()
            iIndex(i) = i
        Next i
        iLastFlipped = UNASSIGNED
        iNumFlipped = 0
        iIndexLimit = 16
        For iFlag = 0 To 7
            iPos = Int(Rnd() * iIndexLimit)
            Tile(iIndex(iPos)).FlagIndex = iFlag
            For i = iPos To iIndexLimit - 2
                iIndex(i) = iIndex(i + 1)
            Next i
            iIndexLimit -= 1
            iPos = Int(Rnd() * iIndexLimit)
            Tile(iIndex(iPos)).FlagIndex = iFlag
            For i = iPos To iIndexLimit - 2
                iIndex(i) = iIndex(i + 1)
            Next i
            iIndexLimit -= 1
        Next iFlag
    End Sub

    Private Sub frmProj12_Load(sender As Object, e As System.EventArgs) Handles Me.Load
        Tile(0).TileRef = picTile0
        Tile(1).TileRef = picTile1
        Tile(2).TileRef = picTile2
        Tile(3).TileRef = picTile3
        Tile(4).TileRef = picTile4
        Tile(5).TileRef = picTile5
        Tile(6).TileRef = picTile6
        Tile(7).TileRef = picTile7
        Tile(8).TileRef = picTile8
        Tile(9).TileRef = picTile9
        Tile(10).TileRef = picTile10
        Tile(11).TileRef = picTile11
        Tile(12).TileRef = picTile12
        Tile(13).TileRef = picTile13
        Tile(14).TileRef = picTile14
        Tile(15).TileRef = picTile14
        Randomize()
    End Sub
    Private Sub TileClicked(ByVal sender As System.Object, _
                            ByVal e As System.EventArgs) Handles _
        picTile0.Click, picTile1.Click, picTile2.Click, picTile3.Click, _
        picTile4.Click, picTile5.Click, picTile6.Click, picTile7.Click, _
        picTile8.Click, picTile9.Click, picTile10.Click, picTile11.Click, _
        picTile12.Click, picTile13.Click, picTile14.Click, picTile15.Click

        Dim picBox As PictureBox
        Dim i, Index As Integer
        picBox = sender
        Index = CInt(picBox.Tag)
        If Tile(Index).Flipped = False Then
        End If
        Tile(Index).TileRef.Image =
            ImageList1.Images(Tile(Index).FlagIndex)
        Tile(Index).Flipped = True
        iNumFlipped += 1
        Select Case iNumFlipped
            Case 1
                iLastFlipped = Index
            Case 2
                If Tile(Index).FlagIndex = Tile(iLastFlipped).FlagIndex Then
                    Tile(Index).Matched = True
                    Tile(iLastFlipped).Matched = True
                    iLastFlipped = UNASSIGNED
                End If
            Case 3
                iLastFlipped = Index
                iNumFlipped = 1
                For i = 0 To 15
                    If Tile(i).Matched = False And i <> Index Then
                        Tile(i).Flipped = False
                        Tile(i).TileRef.Image = ImageList1.Images(EARTH)
                    End If
                Next
        End Select
    End Sub
End Class