Back up the signout.aspx file.
This file is typically available in the following directory:
C:\Program Files\Common Files\Microsoft Shared\web server extensions\ 12\TEMPLATE\LAYOUTS
Open the signout.aspx file.
Replace the lines of code indicated within this step.
function _spBodyOnLoad() [ try [ document.execCommand("ClearAuthenticationCache"); ] catch (e) [] window.close(); ]
function _spBodyOnLoad() [ window.location="https://amHost:amPort/amserver/UI/Logout"; ]
Where amHost and amPort are place holders that you must replace with the fully qualified domain name (FQDN) host name and port number, respectively, of the Access Manager server.
Save and close the signout.aspx file.
Restart the Microsoft IIS 6.0 server using the iisreset command.
Now you can verify the installation of the agent as described in Microsoft Office SharePoint and Outlook Web Access: Verifying a Successful Agent Installation.