ModalPopupExtender with thumbnail and full size image

let me rewrite my question, I have a Ajax Accordion in my web site, Users can add images, in Accordion,I keep the thumbnail and fullsize image's path in Sql Server table, Users can see the thumbnail, and when they click the thumbnail, I use a ModalPopupExtender that open an asp panel to show the full size image, with progress image or preload bar

What is the best way to achieve 开发者_高级运维this?

Thanks in advance

Are you asking how to implement a ModalPopupExtender?

Thanks for your reply,

I am using javascript to unhide the asp panel, and replace the image source with full size image, it is working in IE, but in FireFox,Opera,and Chrome, user have to click several time on thumbnail to see the full size image,for the firts time it shows nothing, this is the problem