VB6 DataGrid: Multiple Selection (Left Mouse Down + SHIFT)

Option Explicit 
 
Private Declare Function GetKeyState Lib "user32" (ByVal nVirtKey As Long) As Integer 
Private Const VK_SHIFT = &H10 
Private LastRow As Long 
Private SelectionCount As Long 
 
'------------------------------------------------------------------------------- 
'http://khoiriyyah.blogspot.com 
'------------------------------------------------------------------------------- 
 
Private Sub Form_Load() 
    'load database 
    With Adodc1 
        .ConnectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=biblio.mdb;Persist Security Info=False" 
        .RecordSource = "Select * from [titles]" 
        .Refresh 
        .Recordset.MoveFirst 
    End With 
    Set DataGrid1.DataSource = Adodc1 
End Sub 
 
Private Sub DataGrid1_SelChange(Cancel As Integer) 
    Call SetSelectionPlusShiftKey(DataGrid1) 
End Sub 
 
Private Sub SetSelectionPlusShiftKey(dtGrid As DataGrid) 
    Dim i As Integer 
    Dim Direction As Integer 
    If GetKeyState(VK_SHIFT) < 0 Then 
        SelectionCount = LastRow - dtGrid.Row 
        If SelectionCount < 0 Then 
            Direction = 1 
        Else 
            Direction = -1 
        End If 
        For i = 0 To SelectionCount Step -Direction 
            DataGrid1.SelBookmarks.Add (dtGrid.GetBookmark(i)) 
        Next i 
    Else 
        LastRow = dtGrid.Row 
    End If 
End Sub 
 
Private Sub Form_Resize() 
    On Error Resume Next 
    DataGrid1.Move 0, 0, Me.ScaleWidth, Me.ScaleHeight 
End Sub