How Can I Fix Reflected XSS Clients in Asp.Net

Question

How can I fix a reflected XSS client problem on ASP.Net? Can anyone help me?

The problem is below:

Reflected XSS Client

Method :

ROW:563

Private Shared Function bindSiteMenu(TSql As String) As Data.DataTable
....
563.                  DRow.Item("Sortby") =  dt1.Rows(i).Item("Sortby").ToString
564.                  dtAll.Rows.Add(DRow)
....
569.          Return dtAll

Method :

Public Shared Function FrontSiteMenuForSMap(ByVal SiteID As Long) As 
Data.DataTable

                ....
529.          Return bindSiteMenu(TSql)

Method :

Protected Sub SiteMap(SitID As Long)

    ....
    27.          Dim dt As Data.DataTable =
    SiteMenuObj.FrontSiteMenuForSMap(SitID)
    ....
    29.              SetNodes(dt, SitID, 0, 0, "")

Method :

ROW:77

Protected Sub SetNodes(ByVal dtTree As Data.DataTable, ByVal SiteID As Long,ByVal ParentId As Long, ByVal Level As Integer, ByVal TreeNumber As String)

....
33.      Protected Sub SetNodes(ByVal dtTree As Data.DataTable, ByVal
SiteID As Long, ByVal ParentId As Long, ByVal Level As Integer, ByVal
TreeNumber As String)
....
36.          rows = dtTree.Select(filterExpr)
37.          If rows.GetUpperBound(0) >= 0 Then
....
47.              For Each row In rows 
48.                  tmpParentId = row.Item("ParentId").ToString
49.                  tmpFDefaultLink = row.Item("FDefaultLink").ToString
50.                  tmpMenuTitle = row.Item("MenuTitle").ToString
51.                  tmpMenuID = row.Item("MenuID").ToString
52.                  tmpSiteID = row.Item("SiteID").ToString
53.                  tmpURL = row.Item("URL").ToString
....
71.                          Url = tmpURL
....
77.                      litF.Text = "<li " & css & "><a href=""" & Url
& """ title=""" & tmpMenuTitle & Title & """>" & tmpNumber & tmpCount &
"." & tmpMenuTitle & "</a><ol>"

Thanks for everyone's help!