About the refresh of updatepanel

Hi:

I meet a problem about updatepanel. I create an button and click event, when user click, it will refresh the 

data in updatepanel; however, the whole page seems refresh, not only the region of updatepanel.

I thinks it may be from the event of autopostback, but how to make the button can invoke the event and 

only change the data in updatepanel. is jquery a solution for that, and how to make it, any suggestion is appreciated

thanks.