Image Preloading for image gallery

suppose i am showing images through datalist control. datalist have 5 rows and 5 columns. all rows and all columns will show a small image. so when i am showing images then it is taking little time. so i want to show a image pre-loader for each image. so at the very beginn开发者_如何学Going when page will be running then many busy indicator will show for each image and when each image will show in the page gradually then image preloader for that image will be invisible. so please guide me how to develop my image gallery in this way.

example site is http://davidwalsh.name/dw-content/lazyload-fade.php

i want the output like above url.

thanks