how to refresh only image control

[harithadotnet]

In my aspx page i am displaying images as small size(thumbnails). when i click on any of the image that image should be displayed as large in the same page of another largeimage control.it is working ,but everytime when click on images total page is refreshing .I want to refresh only that image control...how to o that? I am doing this using asp.net 1.1 and visual studio.net 2003 Is it possible using these???? plz let me know. Thanks in advance.

Haritha