Uncheck Node in TreeView

Sup all.
I been trying to uncheck a node programatically but no luck
does any one know how 2 do this.
sounds simple enough( The "Node.Checked = False" doesnt seem to do the trick)
I want the user to be able to check only 2 nodes at a time but if they check more than 2 then the last one i want it to uncheck it.
thanks in advance.
THIS IS WHAT I HAVE SO FAR:

Private Sub tvProviders_NodeCheck(ByVal Node As MSComctlLib.Node)
DIM iNodesChecked as integer

----Node.Selected = True
-
----If Node.Checked = True Then
-------iNodesChecked = iNodesChecked + 1
----ElseIf Node.Checked = False Then
-------iNodesChecked = iNodesChecked - 1
----End If
-
----If iNodesChecked > 2 And Node.Checked = True Then
-------Node.Checked = False
-------DoEvents
----End If
-
----lblChecked.Caption = iNodesChecked
-
End Sub

Code:

---

tv1.Nodes(1).Checked = False

---

but i cannot get it to work inside the treeview_nodecheck function :(

i don't know why :(