FileUpload1.HasFile is always returning false
<p>I am uploading file using ASP.net File upload control.
My FileUpload1.HasFile is always returning false.</p>

<pre><code>if (FileUpload1.HasFile)
        {
            DBOperations db = new DBOperations();

            try
            {
                FileUpload1.SaveAs(Server.MapPath("~/uploadedImages/" + db.uploadImage(System.IO.Path.GetExtension(FileUpload1.FileName)) + System.IO.Path.GetExtension(FileUpload1.FileName)));
            }
            catch (Exception Ex)
            {
                String he = Ex.Message;
            }
        }
</code></pre>

<p>I am using following ASP.net Code</p>

<pre><code>&lt;asp:UpdatePanel ID="fileUpload" runat="server"&gt;
           &lt;ContentTemplate&gt;
             &lt;Triggers&gt;
                  &lt;asp:AsyncPostBackTrigger ControlID="btnUploadFile" EventName="Click" /&gt;
             &lt;/Triggers&gt;
               &lt;asp:FileUpload ID="FileUpload1" runat="server" /&gt; 
               &lt;asp:Button ID="btnUploadFile" Text="Upload File" runat="server" 
                   onclick="btnUploadFile_Click" /&gt;
                   &lt;br /&gt;
             &lt;asp:RegularExpressionValidator ID="revImage" ControlToValidate="FileUpload1" ValidationExpression="^.*\.((j|J)(p|P)(e|E)?(g|G)|(g|G)(i|I)(f|F)|(p|P)(n|N)(g|G))$" Text="Invalid image type" runat="server" /&gt;

          &lt;/ContentTemplate&gt;
       &lt;/asp:UpdatePanel&gt;
</code></pre>

<p>I have tried even by removing AsyncPostBackTrigger and even by removing Whole asp:updatePanel then also my FileUpload1.HasFile always returns false.</p>
