need help to convert VB code to C# in ASP.net

<%@ Import Namespace="System.Xml" %>

<script language="VB" runat="server">

'Relative file path to XML data
Dim strXmlFilePath as String = Server.MapPath("quiz.xml")

Dim xDoc as XmlDocument = New XmlDocument()
Dim intTotalQuestion as Integer
Dim intQuestionNo as Integer = 1
Dim intScore as Integer = 0
Dim arrAnswerHistory as new ArrayList()

Sub Page_Load(src as Object, e as EventArgs)

    'Load xml data
    xDoc.Load(strXmlFilePath)

    'Start a new quiz?
    If Not Page.IsPostBack Then

        'Yes! Count total question
        intTotalQuestion = xDoc.SelectNodes("/quiz/mchoice").Count

        'Record start time
        ViewState("StartTime") = DateTime.Now

        ShowQuestion(intQuestionNo)
    End If
End Sub


Sub btnSubmit_Click(src as Object, e as EventArgs)

    'Retrieve essential variables from state bag
    intTotalQuestion = ViewState("TotalQuestion")
    intQuestionNo = ViewState("QuestionNo")
    intScore = ViewState("Score")
    arrAnswerHistory = ViewState("AnswerHistory")

    'Correct answer?
    If rblAnswer.SelectedItem.Value = ViewState("CorrectAnswer") Then
        intScore += 1
        arrAnswerHistory.Add(0)
    Else
        arrAnswerHistory.Add(rblAnswer.SelectedItem.Value)
    End If

    'End of quiz?
    If intQuestionNo=intTotalQuestion Then

        'Yes! Show the result...
        QuizScreen.Visible = False
        ResultScreen.Visible = True

        'Render result screen
        ShowResult()

    Else

        'Not yet! Show another question...
        QuizScreen.Visible = True
        ResultScreen.Visible = False
        intQuestionNo += 1

        'Render next question
        ShowQuestion(intQuestionNo)
    End If
End Sub


Sub ShowQuestion(intQuestionNo as Integer)
    Dim xNodeList as XmlNodeList
    Dim xNodeAttr as Object
    Dim strXPath as String
    Dim i as Integer
    Dim tsTimeSpent as TimeSpan

    strXPath = "/quiz/mchoice[" & intQuestionNo.ToString() & "]"

    'Extract question
    lblQuestion.Text = intQuestionNo.ToString() & ". " & xDoc.SelectSingleNode(strXPath & "/question").InnerXml

    'Extract answers
    xNodeList = xDoc.SelectNodes(strXPath & "/answer")

    'Clear previous listitems
    rblAnswer.Items.Clear

    For i = 0 to xNodeList.Count-1

        'Add item to radiobuttonlist
        rblAnswer.Items.Add(new ListItem(xNodeList.Item(i).InnerText, i+1))

        'Extract correct answer
        xNodeAttr = xNodeList.Item(i).Attributes.ItemOf("correct")
        If not xNodeAttr is Nothing Then
            If xNodeAttr.Value = "yes" Then
                ViewState("CorrectAnswer") = i+1
            End If
        End If
    Next

    'Output Total Question
    lblTotalQuestion.Text = intTotalQuestion

    'Output Time Spent
    tsTimeSpent = DateTime.Now.Subtract(ViewState("StartTime"))
    lblTimeSpent.Text = tsTimeSpent.Minutes.ToString() & ":" & tsTimeSpent.Seconds.ToString()

    'Store essential data to viewstate
    ViewState("TotalQuestion") = intTotalQuestion
    ViewState("Score") = intScore
    ViewState("QuestionNo") = intQuestionNo
    ViewState("AnswerHistory") = arrAnswerHistory

End Sub

Sub ShowResult()
    Dim strResult as String
    Dim intCompetency as Integer
    Dim i as Integer
    Dim strXPath as String
    Dim tsTimeSpent as TimeSpan

    tsTimeSpent = DateTime.Now.Subtract(ViewState("StartTime"))

    strResult  = "<center>"
    strResult += "<h3>Quiz Result</h3>"
    strResult += "<p>Points: " & intScore.ToString() & " of " & intTotalQuestion.ToString()
    strResult += "<p>Your Competency: " & Int(intScore/intTotalQuestion*100).ToString() & "%"
    strResult += "<p>Time Spent: " & tsTimeSpent.Minutes.ToString() & ":" & tsTimeSpent.Seconds.ToString()
    strResult += "</center>"

    strResult += "<h3>Quiz Breakdown:</h3>"
    For i = 1 to intTotalQuestion
        strXPath = "/quiz/mchoice[" & i.ToString() & "]"
        strResult += "<b>" & i.ToString() & ". " & xDoc.SelectNodes(strXPath & "/question").Item(0).InnerXml & "</b><br>"
        If arrAnswerHistory.Item(i-1)=0 Then
            strResult += "<font color=""green""><b>Correct</b></font><br><br>"
        Else
            strResult += "<b>You answered:</b> " & xDoc.SelectNodes(strXPath & "/answer[" & arrAnswerHistory.Item(i-1).ToString() & "]").Item(0).InnerXml & "<br>"
            strResult += "<font color=""red""><b>Incorrect</b></font><br><br>"
        End If
    Next

    lblResult.Text = strResult
End Sub

</script>
<html>
<head>
<title>Australian Geography Quiz</title>
</head>

<style>
body {
  font-size: 10pt;
  font-family: verdana,helvetica,arial,sans-serif;
  color:#000000;
  background-color:#eeeedd;
}

tr.heading {
  background-color:#900B08;
}

.button {
    border: 1px solid #000000;
    background-color: #ffffff;
}

</style>

<body>
<span id="QuizScreen" runat="server">
<form runat="server">
<table width="100%" border="0" cellpadding="2" cellspacing="0">
  <tr class="heading">
    <td width="50%"><font color="white"><b>Australian Geography Quiz</b></font></td>
    <td width="50%" align="right"><font color="white"><b>www.codeproject.com</b></font></td>
  </tr>
  <tr>
    <td colspan="2">
      <b><asp:label id="lblQuestion" runat="server" /></b><br>
      <asp:radiobuttonlist
         id="rblAnswer"
         RepeatDirection="vertical"
         TextAlign="right"
         RepeatLayout="table"
         runat="server" /><br>
      <asp:requiredfieldvalidator
         ControlToValidate="rblAnswer"
         ErrorMessage="Please pick an answer!"
         runat="server" /><br>
      <asp:button id="btnSubmit" class="button" text="  Next  " onClick="btnSubmit_Click" runat="server" />
    </td>
  </tr>
  <tr class="heading">
    <td width="50%"><font color="white"><b>Total <asp:label id="lblTotalQuestion" runat="server" /> questions</b></font></td>
    <td width="50%" align="right"><font color="white"><b>Time spent <asp:label id="lblTimeSpent" runat="server" /></b></font></td>
  </tr>
</table>
</form>
</span>
<span id="ResultScreen" runat="server">
<asp:label id="lblResult" runat="server" />
</span>
</body>
</html>