title: Web Browser display a warning 'Confirm Form Resubmission' when user press F5 or refresh the page
body: <p>I have a very simple asp page:</p>
  
  <p>Default.aspx:</p>
  
  <pre><code>&lt;%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %&gt;
  
  &lt;!DOCTYPE html&gt;
  
  &lt;html xmlns="http://www.w3.org/1999/xhtml"&gt;
  &lt;head runat="server"&gt;
  &lt;meta http-equiv="Content-Type" content="text/html; charset=utf-8"/&gt;
      &lt;title&gt;&lt;/title&gt;
  &lt;/head&gt;
  &lt;body&gt;
      &lt;form id="form1" runat="server"&gt;
      &lt;div&gt;
          &lt;asp:GridView ID="GridView1" runat="server" 
              AllowPaging="true" PageSize="4" 
              OnPageIndexChanging="GridView1_PageIndexChanging"&gt;
  
          &lt;/asp:GridView&gt;
      &lt;/div&gt;
      &lt;/form&gt;
  &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  
  <p>Default.aspx.cs code-behind:</p>
  
  <pre><code>public partial class _Default : System.Web.UI.Page
  {
      private class FakeData
      {
          public string Name { get; set; }
          public int Age { get; set; }
      }
      private List&lt;FakeData&gt; fakeData;
  
      void InitFakeData()
      {
          fakeData = new List&lt;FakeData&gt;()
          {
              new FakeData(){ Age = 8, Name = "John"},
              new FakeData(){ Age = 9, Name = "Carl"},
              new FakeData(){ Age = 7, Name = "June"},
              new FakeData(){ Age = 6, Name = "Ellie"},
              new FakeData(){ Age = 9, Name = "Betty"},
              new FakeData(){ Age = 10, Name = "Sam"},
              new FakeData(){ Age = 5, Name = "Peter"},            
          };      
      }
  
      void ShowData()
      {
          InitFakeData();
          GridView1.DataSource = fakeData;
          GridView1.DataBind();
      }
  
      protected void Page_Load(object sender, EventArgs e)
      {
          if (!IsPostBack)
              ShowData();
      }
  
      protected void GridView1_PageIndexChanging(object sender, GridViewPageEventArgs e)
      {
          GridView1.PageIndex = e.NewPageIndex;
          ShowData();
      }
  }
  </code></pre>
  
  <p><strong>Result</strong>:</p>
  
  <p><img src="https://i.stack.imgur.com/MjXtu.png" alt="enter image description here"></p>
  
  <p><strong>The problem</strong>:</p>
  
  <p>If the user press F5 or refresh the page in GridView Page Index 2 the web browser pop-ups the following message:</p>
  
  <p><em>Confirm Form Resubmission
  The page you 're looking for used information that you entered . Back to repeat could result in some action. Do you want to continue?</em></p>
  
  <p><strong>Question</strong>:</p>
  
  <p>How can you avoid the browser to display that message? (and show the GridView Page Index 'n' without any web browser warning pop-up)</p>
  
  <p>PS: Tested with Chrome, Firefox and IE11</p>