สอบถามทำให้เมนู active <li> เปลี่ยนไปตามเมนูที่กดค่ะ

<nav class="navbar navbar-default navbar-fixed-top">
      <div class="container">
        <div class="navbar-header">
          <button type="button" class="navbar-toggle collapsed" data-toggle="collapse" data-target="#navbar" aria-expanded="false" aria-controls="navbar">
            <span class="sr-only">Risk Management</span>
            <span class="icon-bar"></span>
            <span class="icon-bar"></span>
            <span class="icon-bar"></span>
          </button>
          <a class="navbar-brand" href="?page=page">Brand</a>
        </div>
        <div id="navbar" class="navbar-collapse collapse">
          <ul class="nav navbar-nav">
            <li class="active"><a href="?page=page">Home</a></li>
            <li><a href="?page=ir&action=ins">หน้า1</a></li>
            <li><a href="?page=showir">หน้า2</a></li>
            <li><a href="?page=re&action=show">หน้า3</a></li>
            <li><a href="?page">แจ้งเตือน</a></li>
          </ul>
        </div>
      </div>
    </nav>

    <div class="container">
        <div class="container theme-showcase" role="main">
            <asp:Panel ID="hplContainer" runat="server"></asp:Panel>  
      </div>
<hr>
      <footer>
        <p>&copy; 2016</p>
      </footer>
    </div>

Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        If Session("strUser") = "" Or Session("strUser") = Nothing Then
            Response.Redirect("login.aspx")
            Response.End()
            Exit Sub
        Else
            Dim objCtrl As Control
            Dim strPage, strAction, irid, rptName As String
            strPage = Request.QueryString("page")
            strAction = Request.QueryString("action")
            irid = Request.QueryString("irid")
            rptName = Request.QueryString("rptName")
            Select Case strPage
                Case "ir"
                    Select Case strAction
                        Case "ins" 
                            objCtrl = LoadControl("~/page1.ascx")
                        Case "edt" 
                            objCtrl = LoadControl("~/page2.ascx")
                        Case "del" 
                            objCtrl = LoadControl("~/page3.ascx")
                    End Select
                    Exit Select
            End Select

            Me.hplContainer.Controls.Add(objCtrl)
            
        End If
    End Sub