"Please wait" div used in ASP classic never shows up in ASP.NET 2.0 environment

I'm sure there's an easy way to do this, I'm just not aware of it. In our ASP classic environment, whenever we have a page that does any kind of processing, we use client side scripting to display a div and table that shows "Please wait while we process your request..." text. On page load, for example, while a db call takes place, or when submitting a form, loading an iframe, doing a server.execute/transfer, etc. All works fine in that legacy environment. In ASP.NET 2.0, however, I can't seem to get divs to display while a doing a intra-page process using server-side code. One page in particular as an example - I have two drop downs and a submit button. Additionally, I have several tables that are inside a div and are hidden by default. The submit button does several SQL calls and returns datasets that populate the textboxes and labels, which when done make the div visible. That works. I have another table on the same page inside a div with the "please wait" text. It is also hidden by default. I only want it to show up temporarily while the code behind the Submit button does its thing. Even though I FIRST unhide the div in my code before I do the SQL stuff, it never is displayed. The code launches right into the SQL and returns the other table with the data in it.

Is there some way to do what I'm trying to do, using server side code...with everything on a single page and not using frames?

Thanks for any suggestions!