Running treeview to call out tabcontrol error

[crystalelle]

Hi,

I am facing trouble with the following code.

Public Class Form1
Private PreviousTab As TabControl
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Me.Load
With TreeView1.Nodes.Item("AdminMenu")
.Nodes.Item("AddCustomer").Tag = TabAddCust
.Nodes.Item("DeleteCust").Tag = TabDeleteCust
End With
End Sub


Private Sub TreeView1_AfterSelect(ByVal sender As System.Object, ByVal e As System.Windows.Forms.TreeViewEventArgs) Handles TreeView1.AfterSelect
If PreviousTab IsNot Nothing Then
PreviousTab.Visible = False
End If
If e.Node.Tag IsNot Nothing Then
Dim ActiveTab As TabControl = CType(e.Node.Tag, TabControl)
ActiveTab.Visible = True
ActiveTab.Dock = DockStyle.Fill
PreviousTab = ActiveTab
End If
End Sub

When I run it this 2 lines come out with the message of NullReferenceException was unhandles object reference not set to an instance object.

.Nodes.Item("AddCustomer").Tag = TabAddCust
.Nodes.Item("DeleteCust").Tag = TabDeleteCust

Please help.