Asp.net page timeouts altough button is clicked in an update panel - asp.net

Question

I have an asp.net page for a simple blog which looks like
<asp:TextBox ID="txtContent" runat="server" TextMode="MultiLine">Default Text</asp:TextBox>
<asp:LinkButton ID="lbSend" runat="server" Text="Send" OnClick="lbSend_Click" />
<script type="text/javascript">
//some javascript to click btnSave in update panel for every five minutes.
</script>
<asp:UpdatePanel ID="upSave" runat="server" Style="display: none;">
<ContentTemplate>
<asp:Button ID="btnSave" runat="server" Text="Button" OnClick="btnSave_Click" />
</ContentTemplate>
<Triggers>
<asp:AsyncPostBackTrigger ControlID="btnSave" EventName="Click" />
</Triggers>
</asp:UpdatePanel>
And in the code behind
protected void lbSend_Click(object sender, EventArgs e)
{
//Gets UserID from session and saves it to table A with txtContent
}
protected void btnSave_Click(object sender, EventArgs e)
{
//Gets UserID from session and saves it to table B with txtContent
}
Everything works okay. I fill the form and insert the content into tables with lbSend or btnSave. JavaScript is also clicking btnSave. However when it takes long to fill txtContent, about 40 minutes or more, the page is like expired. Clicking lbSend refreshes the page in an asynchronous way and everything you have written is gone. It is like the page have sleeped and wakes ups when I click. And lbSend works normal when you click it again.
What is the reason of this "sleep" altough btnSave continues to communicate with server? And how can I prevent it.

Answer 1

You are doing an Ajax post. Since it is an asynchronous post your browser happily moves on and you don't notice a problem until there is an error. If it was not Ajax then the whole page would have refreshed and you would have seen an error - assuming you display errors in a friendly format.
While implementing Ajax you should implement your own error handler so you can display to the user that an error has occurred. Also, you should implement a floating div or dialog that prevents the user from using your web page until the Ajax request has completed. I realize 40minutes is really really bad for a simple insert but I will leave that for your DBA to fix.
Let's talk about the floating div or dialog or "modal popup". You want to open it in the before_Ajax_send function and close it in your after_Ajax_receive function. Please refer to your Ajax library documentation for more information on these functions.
When you implement this dialog box it will enhance your user experience because it will let the user know that your application is doing something so please hold your horses.
Hope this helps.