title: Label.Visible=true is not working
body: <p>I have an aspx page (a login page). When a user enters userno &amp; pw fields and clicks on "Ok" button, the user redirects to Default.aspx page. If user does not login succesfully, a label control will show up (Label.visible will be true in codebehind). </p>
  
  <p>Somehow Visible=true is not working.</p>
  
  <p>This is Html:</p>
  
  <pre><code>&lt;%@ Page Title="" Language="C#" MasterPageFile="~/SiteEntree.master" AutoEventWireup="true" Inherits="WebApp.Login" Codebehind="Login.aspx.cs" %&gt;
  
  &lt;asp:Content ID="Content1" ContentPlaceHolderID="head" Runat="Server"&gt;
  &lt;/asp:Content&gt;
  &lt;asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" Runat="Server"&gt;
  
         &lt;div id="isDiv"&gt;
         &lt;div id="divNoteBox"&gt;
         &lt;/div&gt;
         &lt;div id="loginBox" class="formLayout"&gt;
               &lt;label&gt;User No: &lt;/label&gt;&lt;asp:TextBox runat="server" ID="txtUno" /&gt;
               &lt;br /&gt;
               &lt;label&gt;Password:&lt;/label&gt;&lt;asp:TextBox runat="server" ID="txtPw" /&gt;
             &lt;asp:Label runat="server" Visible="false" ID="lblMsg" Text="a message to warn.." /&gt;
               &lt;asp:LinkButton runat="server" ID="lbtn" Text="Ok" OnClick="lbtn_Click" CssClass="lbClass" /&gt;
         &lt;/div&gt;  
      &lt;/div&gt;
  &lt;/asp:Content&gt;
  </code></pre>
  
  <p>And Codebehind:</p>
  
  <pre><code>    public partial class Login : System.Web.UI.Page
          {
              protected void Page_Load(object sender, EventArgs e)
              {
  
              }
  
      protected void lbtn_Click(object sender, EventArgs e)
              {
                  using (DBEntities context = new DBEntities())
                  {
                      int? val = context.checkUser(Convert.ToInt32(txtUno.Text), txtPw.Text).SingleOrDefault();
                      if(val!=null)
                      {
                          int? r = val;
                          if (r == -1)
                          {
                              Response.Redirect("Login.aspx");
                              lblMsg.Visible = true;
                          }
                          else if (r == 1)
                          {
                              Response.Redirect("Default.aspx");
                          }
                  }
              }
       }
  }
  </code></pre>
  
  <p>Could you help please, Thanks.</p>