Javascript显示div在回发后消失了

I have a page that has a button that displays the contents of a div with javascript. I have a ASP.net validator control that does a postback. If I step though my javascript in firebug the page still has the div visible, and if i just let the page run normally the javascript makes the div visible for a second then the postback resets the visibility to off when it reloads. How can I stop this from happening?I have a page that has a button that displays t