title: upload file not working in updatepanel
body: <p><strong><em>I DONT WANNA GET MY PAGE TO BE GET REFRESH OR POSTBACK</em></strong></p>
  
  <p>So I am trying uploading file in updatepanel but onclicking upload button the validation check shows that there is no file</p>
  
  <p>my html code is</p>
  
  <pre><code>&lt;asp:UpdatePanel ID="UpdatePanel16" runat="server" UpdateMode="Conditional"&gt;
  &lt;ContentTemplate&gt;
   &lt;asp:FileUpload ID="fp_upload" runat="server" /&gt;&amp;nbsp;&amp;nbsp;
  &lt;asp:Button ID="btn_browse" runat="server" Text="Upload" OnClick="btn_browse_Click" /&gt;
     &lt;/ContentTemplate&gt;  
  &lt;/asp:UpdatePanel&gt;
  </code></pre>
  
  <p>It seems to be </p>
  
  <p><img src="https://i.stack.imgur.com/9WSso.jpg" alt="enter image description here"></p>
  
  <p>my .cs code is </p>
  
  <pre><code>protected void btn_browse_Click(object sender, EventArgs e)
  {
     if (fp_upload.HasFile)
      {
          Response.Write("contains file");
      }
      else
      {
         Response.Write("no file");
      }
  }
  </code></pre>
  
  <p>when I used to browse the file and click on upload button every times it goes in else condition. Whats the problem.</p>
  
  <p><strong><em>ALSO I DONT WANNA GET MY PAGE TO BE GET REFRESH OR POSTBACK</em></strong></p>