title: UpdateProgress not appearing on second click of same button
body: <p>UpdateProgress appear first time, when i click on the button btnSubmit. But when i click the same button next time UpdateProgress not appearing. But all other things works well. I am using this UpdateProgress to show a GIF image while sending E-mail to client. For the first client UpdateProgress appear but for second to other 'n' UpdateProgress not appearing. Please help i am asking this question Second time in Stack Overflow</p>
  
  <p>Code below shows my UpdateProgress</p>
  
  <pre><code> &lt;asp:UpdatePanel ID="up1" runat="server"&gt;
          &lt;ContentTemplate&gt;
              &lt;asp:UpdateProgress ID="updProgress"
                  runat="server"&gt;
                  &lt;ProgressTemplate&gt;
                      &lt;div class="modal"&gt;
                          &lt;div class="center"&gt;
                              &lt;span style="padding-left: 10px"&gt;&lt;b&gt;Please Wait..&lt;/b&gt;&lt;/span&gt;
                              &lt;img alt="" src="../images/Preloader_3.gif" width="50" height="50" /&gt;
                          &lt;/div&gt;
                      &lt;/div&gt;
                  &lt;/ProgressTemplate&gt;
              &lt;/asp:UpdateProgress&gt;
          &lt;/ContentTemplate&gt;
          &lt;Triggers&gt;
              &lt;asp:AsyncPostBackTrigger ControlID="btnSubmit" EventName="Click" /&gt;
          &lt;/Triggers&gt;
      &lt;/asp:UpdatePanel&gt;
  </code></pre>
  
  <p>Code below shows my button that trigger the UpdateProgress</p>
  
  <pre><code> &lt;asp:UpdatePanel ID="UpdatePanel1" runat="server"&gt;
      &lt;Triggers&gt;
      &lt;asp:AsyncPostBackTrigger ControlID="btnSubmit" EventName="Click" /&gt;
      &lt;/Triggers&gt;
      &lt;ContentTemplate&gt;
      &lt;div class="form-group row"&gt;
          &lt;div class="col-sm-6"&gt;
              &lt;div class="col-sm-6"&gt;
                  &lt;asp:Button ID="btnSubmit" OnClick="btnSubmit_Click"
                      OnClientClick="javascript:return btnSubmit();" CssClass="btn btn-primary"
                      runat="server" Text="Submit" /&gt;
                  &lt;a href="assignment.aspx?sid=&lt;%=Request.QueryString["sid"] %&gt;" class="btn btn-default"&gt;Cancel&lt;/a&gt;
              &lt;/div&gt;
          &lt;/div&gt;
      &lt;/div&gt;
      &lt;/ContentTemplate&gt;
      &lt;/asp:UpdatePanel&gt;
  </code></pre>
  
  <p>Code Behind CS</p>
  
  <pre><code> protected void btnSubmit_Click(object sender, EventArgs e)
      {
          updProgress.Visible = true;
          SendEmail(Convert.ToInt32(drpDiv.Text));
          updProgress.Visible = false;
      }
  </code></pre>