This Sticky Footer code needs jQuery and will position the element footer with id “myfooter” at the bottom if the page length is shorter than the browser window length and will place it in the normal flow if the page is longer or equal to the browser window length.

.NET Ajax UpdatePanel & the Sticky Footer

If you're a .NET developer and using the ScriptManager and Ajax UpdatePanels you'll need a call to the javascript fonction positionFooter() after an ajax partial postback, because the page length will change when the updatepanel updates it’s content. So just add this code to the page or master page where your Update panel is defined, Just change "up1" with your UpdatePanel ID :

if (IsPostBack)
{
ScriptManager.RegisterStartupScript(up1, up1.GetType(), "ppf", "positionFooter();", true);
}