I'm trying to Preview before I print and I'm getting this error. Can somebody tell me why.

Code:
Private Sub Preview_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Preview.Click
        Dim ErrReport As PrintDocument
        Dim dlgPreview As PrintPreviewDialog

        ErrReport = New PrintDocument()
        dlgPreview = New PrintPreviewDialog()
        AddHandler ErrReport.PrintPage, AddressOf PrintReport

        dlgPreview.Document = ErrReport
        dlgPreview.ShowDialog()

    End Sub
*** my error

************** Exception Text **************
System.NullReferenceException: Object reference not set to an instance of an object.
at System.Windows.Forms.PrintPreviewControl.CalculatePageInfo()
at System.Windows.Forms.Control.InvokeMarshaledCallbacks()

PrintReport is where the report is created.

Thanks.