The link created by treeview does not work

[asiaenforcer]

The code generated treeview on masterpage side menu, but the link does not work.
Upon clicking, there is a small error message says that the objectdoes not supported this method or property.

Here is the javascript:
function chkGiveAlertOrNot(targetPage)
{
var theLink = document.URL;
var haveAlert=document.getElementById("<%=needAlert.ClientID %>").value;
var curLang="<%=Session("chosenLang") %>";
var folderName="Eng";

if (curLang=="en-us")
{
folderName = "Eng";
} else if (curLang=="zh-hk") {
folderName = "Chi";
}
if (theLink.indexOf('TaskEditor') > 0)
{
var haveChange = chkLength();
if (haveChange == false)
{
haveAlert = "F";
}
}

if (haveAlert == 'T')
{
if (window.confirm('<%= confirmLeavePage %>'))
{
var currentLoc=location.href;

switch(targetPage)
{
...
case "VS":
if (currentLoc.indexof("/options/") == -1)
{
location.href="ViewSTD.aspx";
}
else
{
location.href="../ViewSTD.aspx";
}
break;
...
}
}
} else {
var currentLoc=location.href;
switch(targetPage)
{
...
case "VS":
if (currentLoc.indexof("/options/") == -1)
{
location.href = "ViewSTD.aspx";
}
else
{
location.href = "../ViewSTD.aspx";
}
break;
...
}
}
}

Here is the code (partial):
Try
If Not (Session("LoginUser") Is Nothing) Then
oUser = Session("LoginUser")

Select Case e.Node.Text
Case Resources.treeview.treeHome
Dim newLevel2Node1 As TreeNode = New TreeNode(Resources.treeview.treeTask, "Task")
newLevel2Node1.PopulateOnDemand = True
node.ChildNodes.Add(newLevel2Node1)




sqlBOH = "Select USERS.user_role AS UserRole from USERS "
sqlBOH = sqlBOH & "where users.user_guid = '" & oUser.Id.ToString & "' "
conn_rBOH.Open()
sqlcmdBOH = New SqlCommand(sqlBOH, conn_rBOH)
sqlresultBOH = sqlcmdBOH.ExecuteReader
While sqlresultBOH.Read
Session("BOHUserRole") = sqlresultBOH.Item("UserRole").ToString.ToUpper.Trim
If sqlresultBOH.Item("UserRole").ToString.ToUpper.Trim = "RM" Or sqlresultBOH.Item("UserRole").ToString.ToUpper.Trim = "AM" Or sqlresultBOH.Item("UserRole").ToString.ToUpper.Trim = "BOTH" Then
Dim newLevel2Node2 As TreeNode = New TreeNode(Resources.treeview.treeBOH, "BOH")
newLevel2Node2.PopulateOnDemand = True
node.ChildNodes.Add(newLevel2Node2)
'newLevel2Node2 = New TreeNode(Resources.treeview.treeSTD, "STD")
'newLevel2Node2.PopulateOnDemand = True
'node.ChildNodes.Add(newLevel2Node2)
End If

End While
sqlresultBOH.Close()
conn_rBOH.Close()

'sqlSTD = "Select USERS.user_role AS UserRole from USERS "
'sqlSTD = sqlSTD & "where users.user_guid = '" & oUser.Id.ToString & "' "
'conn_rSTD.Open()
'sqlcmdSTD = New SqlCommand(sqlSTD, conn_rSTD)
'sqlresultSTD = sqlcmdSTD.ExecuteReader
'While sqlresultSTD.Read
' Session("STDUserRole") = sqlresultSTD.Item("UserRole").ToString.ToUpper.Trim
' If sqlresultSTD.Item("UserRole").ToString.ToUpper.Trim = "RM" Or sqlresultSTD.Item("UserRole").ToString.ToUpper.Trim = "AM" Then
' Dim newLevel2Node3 As TreeNode = New TreeNode(Resources.treeview.treeSTD, "STD")
' newLevel2Node3.PopulateOnDemand = True
' node.ChildNodes.Add(newLevel2Node3)
' End If
'End While
'sqlresultSTD.Close()
'conn_rSTD.Close()

...
Case Resources.treeview.treeBOH
If viewBOHAdded = False Then
Dim newLevel3Node1 As TreeNode = New TreeNode(Resources.treeview.treeViewBOH, "ViewBOH", "", "javascript:chkGiveAlertOrNot('VB');", "_self")
newLevel3Node1.ToolTip = "View BOH"
newLevel3Node1.PopulateOnDemand = False
node.ChildNodes.Add(newLevel3Node1)
Dim stdnode As TreeNode = New TreeNode(Resources.treeview.treeViewSTD, "ViewSTD", "", "javascript:chkGiveAlertOrNot('VS');", "_self")
stdnode.ToolTip = "View STD"
stdnode.PopulateOnDemand = False
node.ChildNodes.Add(stdnode)
'newLevel3Node1 = New TreeNode(Resources.treeview.treeViewSTD, "ViewSTD", "", "javascript:chkGiveAlertOrNot('VS');", "_self")
'newLevel3Node1.ToolTip = "View STD"
'newLevel3Node1.PopulateOnDemand = False

'newLevel3Node1.ValuePath = "Inventory/ViewSTD.aspx"
'node.ChildNodes.Add(newLevel3Node1)
viewBOHAdded = True
End If

'Case Resources.treeview.treeSTD
' If viewSTDAdded = False Then
' Dim newLevel3Node3 As TreeNode = New TreeNode(Resources.treeview.treeViewSTD, "ViewSTD", "", "javascript:chkGiveAlertOrNot('VS');", "_self")
' newLevel3Node3.ToolTip = "View STD"
' newLevel3Node3.PopulateOnDemand = False
' node.ChildNodes.Add(newLevel3Node3)
' 'newLevel3Node3 = New TreeNode(Resources.treeview.treeViewSTD, "ViewSTD", "", "javascript:chkGiveAlertOrNot('VS');", "_self")
' 'newLevel3Node3.PopulateOnDemand = False
' 'node.ChildNodes.Add(newLevel3Node3)
' viewSTDAdded = True
' End If
...

...
End Select
End If

Any help would be most appreciated thank you.