title: Unable to download file using AsyncPostBackTrigger in RadGrid
body: <p>Hi all I am using RadGrid in my application, as I want my RadGrid not to refresh I had my RadGrid in an Update Panel as follows</p>
  
  <pre><code>&lt;asp:UpdatePanel ID="UpdatePanel1" runat="server" UpdateMode="Always"&gt;
              &lt;Triggers&gt;
              &lt;asp:AsyncPostBackTrigger ControlID="RadGrid1" EventName="ItemCommand" /&gt;
                  &lt;%--&lt;asp:PostBackTrigger ControlID="RadGrid1" /&gt;--%&gt;
              &lt;/Triggers&gt;
              &lt;ContentTemplate&gt;
                  &lt;telerik:RadGrid ID="RadGrid1" runat="server" AutoGenerateColumns="false" OnItemCommand="RadGrid1_ItemCommand"
                      OnNeedDataSource="RadGrid1_NeedDataSource"&gt;
                      &lt;MasterTableView Width="950" AutoGenerateColumns="false" DataKeyNames="EmpID" GridLines="None"
                          TableLayout="Auto"&gt;
                          &lt;Columns&gt;
                              &lt;telerik:GridBoundColumn DataField="EmpID" HeaderText="Emp ID" ReadOnly="true" HeaderStyle-HorizontalAlign="Left"
                                  ItemStyle-HorizontalAlign="Left" UniqueName="EmpID" FilterControlWidth="30px"
                                  AutoPostBackOnFilter="true" CurrentFilterFunction="Contains" /&gt;
                              &lt;telerik:GridButtonColumn DataTextField="ButtonName" ItemStyle-ForeColor="Blue" CommandName="Generate"
                                  ConfirmTextFields="ButtonName" ConfirmTextFormatString="Would you like to  {0} ACH file ?"
                                  ConfirmDialogType="RadWindow" Reorderable="false" UniqueName="ButtonName" ConfirmTitle="ACH File"&gt;
                              &lt;/telerik:GridButtonColumn&gt;
                              &lt;telerik:GridBoundColumn DataField="EmployeeName" HeaderText="Employee Name" ReadOnly="true"
                                  HeaderStyle-HorizontalAlign="Left" ItemStyle-HorizontalAlign="Left" UniqueName="EmployeeName"
                                  FilterControlWidth="60px" AutoPostBackOnFilter="true" CurrentFilterFunction="Contains" /&gt;
                          &lt;/Columns&gt;
                      &lt;/MasterTableView&gt;
                  &lt;/telerik:RadGrid&gt;
              &lt;/ContentTemplate&gt;
          &lt;/asp:UpdatePanel&gt;
  </code></pre>
  
  <p>When I click on download button I am unable to download the file this is my code in Itemcommand</p>
  
  <pre><code>protected void RadGrid1_ItemCommand(object sender, Telerik.Web.UI.GridCommandEventArgs e)
      {
          if (e.CommandName == "Generate")
          {
              Response.ContentType = "text/plain";
              Response.AppendHeader("Content-Disposition", "attachment;filename= errorLog.txt");
              Response.AddHeader("content-length", "0");
              Response.Flush();
              Response.End();
          }
      }
  </code></pre>
  
  <p>Can some one help me how can I work out this using <code>AsyncPostBackTrigger</code></p>