XML paging using XML + XSL + CSS

Imports System.IO
Imports System.Xml
Imports System.Xml.Xsl
Imports System.Xml.XPath

Public Class XMLReader
    Inherits System.Web.UI.Page

    Public xmlDoc As New XmlDocument
    Public xslDoc As New Xml.Xsl.XslTransform
    Public pageSize As String = 5

    Public Sub initXml()
        Dim xmlDocStr = Request.PhysicalApplicationPath & "guestbook.xml"
        Dim xslDocStr = Request.PhysicalApplicationPath & "guestbook.xsl"

        ' Load the dom
        If File.Exists(xmlDocStr) Then
            Try
                xmlDoc.Load(xmlDocStr)
            Catch e As Exception
                Response.Write("<B>Error in XML File:</b> " & e.Message)
                Response.End()
            End Try
        Else
            xmlDoc.LoadXml("<guestbook></guestbook>")
        End If

        ' Load the xsl
        If File.Exists(xslDocStr) Then
            Try
                xslDoc.Load(xslDocStr)
            Catch e As Exception
                Response.Write("<B>Error in XSL File:</b> " & e.Message)
                Response.End()
            End Try
        Else
            Response.Write("<B>Error in XSL File:</b> file not found.")
            Response.End()
        End If
    End Sub


    Public Function buildPageHTML()
        Dim counter = 1
        Dim pagelink = ""

        Dim allNodes As XmlNodeList = xmlDoc.SelectNodes("//guestbook/entry")

        Dim pages As Integer = allNodes.Count / pageSize
        If pages <> Int(pages) Then pages = Int(pages) + 1

        For counter = 1 To pages + 1
            pagelink &= "<a href=""" & Request.ServerVariables("SCRIPT_NAME") & "?page=" & counter & """>" & counter & "</a>&#160;"
        Next

        Return pagelink
    End Function


    Public Function Display()
        Dim currentPage = Request.QueryString("page")
        Dim xsltParams As New XsltArgumentList
        If currentPage = 0 Then currentPage = 1

        If currentPage - 1 = 0 Then
            xsltParams.AddParam("start", "", 1)
        Else
            xsltParams.AddParam("start", "", ((currentPage - 1) * pageSize) + 1)
        End If

        xsltParams.AddParam("end", "", ((currentPage - 1) * pageSize) + pageSize)
        xsltParams.AddParam("link", "", buildPageHTML)

        Try
            xslDoc.Transform(xmlDoc, xsltParams, Response.OutputStream, Nothing)
        Catch e As Exception
            Response.Write(e.Message)
        End Try
    End Function


    Private Sub XMLReader_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles MyBase.Load
        initXml()
    End Sub
End Class