I have a sign-in box in my webpage which is inside an UpdatePanel
There are many ways to do this but I love to use this code because it works well when used in many different circumstances. This is with a 5 second delay.
HtmlMeta oScript = new HtmlMeta();
oScript.Attributes.Add("http-equiv", "REFRESH");
oScript.Attributes.Add("content", "5; url='http://www.myurl.com/'");
Page.Header.Controls.Add(oScript);