'ERROR: An unhandled exception of type 'System.NullReferenceException' occurred in pog.exe

Private Sub ToolStripButton45_Click(sender As Object, e As EventArgs) Handles ToolStripButton45.Click
        tcViewer.TabPages.Add(New ViewerTabPage(tcViewer))
        MsgBox(tcViewer.Controls("picSource0").Name)
    'err here
End Sub

 Class ViewerTabPage
        Inherits TabPage

        Private pnLeftTop As New Panel
        Private pnRightTop As New Panel
        Private pnBottom As New Panel

        Public picSource As New PictureBox
        Private txtZoom As New TextBox
        Private rtSourceContent As New RichTextBox
        Private rtNotesSource As New RichTextBox

        Private ToolStripRT As New ToolStrip
        Private ToolStripB As New ToolStrip
        Private tbZoom As New TrackBar


        Sub New(targettabcontrol As TabControl)

            MyBase.New()

            Me.SuspendLayout()


            Me.Controls.Add(pnLeftTop)
            With pnLeftTop
                .Anchor = AnchorStyles.Left Or AnchorStyles.Top
                .Location = New Point(31, 3)
                .BackColor = Color.Blue
                .Width = (targettabcontrol.Width / 2) - 7 - 30
                .Height = (targettabcontrol.Height / 10) * 6.5 '65%
                .Name = "XXX"
                '.Visible = False
            End With

            Me.Controls.Add(tbZoom)
            With tbZoom
                .Orientation = Orientation.Vertical
                .Location = New Point(0, 3)
                .Height = pnLeftTop.Height
                .Width = 30
            End With

            Me.Controls.Add(pnRightTop)
            With pnRightTop
                .Anchor = AnchorStyles.Right Or AnchorStyles.Top
                .Location = New Point(-(targettabcontrol.Width / 2) + 205, 3)
                .BackColor = Color.Red
                .Width = (targettabcontrol.Width / 2) - 7 - 33
                .Height = (targettabcontrol.Height / 10) * 6.5 '65%
                .Name = "YYY"

                '.Visible = False
            End With

            Me.Controls.Add(ToolStripRT)
            With ToolStripRT
                .AutoSize = False
                .LayoutStyle = ToolStripLayoutStyle.VerticalStackWithOverflow
                .Size = New Point(33, pnRightTop.Height - 1)
                .BackColor = Color.Aqua
                .Dock = DockStyle.None
                .Left = targettabcontrol.Width - 40
                .Top = 3
            End With

            Me.Controls.Add(pnBottom)
            With pnBottom
                .Anchor = AnchorStyles.Bottom
                .Location = New Point(-390, -((targettabcontrol.Height / 10) * 3.5) + 130) 'pnLeftTop.Height + 10)
                .BackColor = Color.Green
                .Width = (targettabcontrol.Width) - 10 - 33
                .Height = (targettabcontrol.Height / 10) * 3.5 '65%
                .Name = "ZZZ"
            End With

            Me.Controls.Add(ToolStripB)
            With ToolStripB
                .AutoSize = False
                .LayoutStyle = ToolStripLayoutStyle.VerticalStackWithOverflow
                .Size = New Point(33, pnBottom.Height - 1)
                .BackColor = Color.Bisque
                .Dock = DockStyle.None
                .Top = ToolStripRT.Height + 5
                .Left = targettabcontrol.Width - 40
            End With


            pnLeftTop.Controls.Add(picSource)
            With picSource
                .Name = "picSource" & targettabcontrol.TabPages.Count - 1
                MsgBox(.Name)

                .BackColor = Color.Yellow

                .Dock = DockStyle.Fill
                .BackgroundImageLayout = ImageLayout.Zoom
            End With

            pnLeftTop.Controls.Add(txtZoom)
            With txtZoom
                .Visible = False
            End With

            pnRightTop.Controls.Add(rtSourceContent)
            With rtSourceContent
                .BackColor = Color.Purple
                .Dock = DockStyle.Fill
            End With

            pnBottom.Controls.Add(rtNotesSource)
            With rtNotesSource
                .BackColor = Color.AliceBlue
                .Dock = DockStyle.Fill
            End With


            Me.ResumeLayout(False)
        End Sub
    End Class