CSS curtain while AJAX is processing

I need a CSS curtain for my AJAX waiting. They attached screen shot is what I am looking for.
I want the users to know that its looking up data and they need to wait. Do I need jQuery or do we have access to this?


You can find a simple example of similar functionality here:
http://www.dhtmlx.com/docs/products/dhtmlxGrid/samples/14_loading_big_datasets/12_pro_srnd_load_notification.html