show progress image while loading asp.net page

I have an asp.net page, with couple of Divs, some of these div's get the image path from database and show the image in a smaller version (thumbnail). and as soon as user click on thumbnail, I use ajax Modal popup to show the full size image, what I need to have is to have a progree image(gif), on every thumbnail image while loading the asp.net page for the first time, I konw that it is possible to use UpadePanel, but I need the actual working cod开发者_如何转开发e,or any other way to achieve this,

Thanks in advance

Well, if you are posting back, udpate panel can work; but you can programmably in JS do this yourself, or also consider using a JS plugin like lightbox: http://www.huddletogether.com/projects/lightbox2/

Which has that feature and looks very cool.