Logoutfunktion i DW

Nedenstående er sakset fra min side hvorpå jeg har placeret logout funktionen (indbygget i DW). Siden hvorpå logoutet er placeret er inkluderet i mit sites andre sider.

Jeg får en fejlmeddelelse når jeg bruger denne funktion. (Response object error 'ASP 0156 : 80004005' Header Error
/menu.asp, line 20
The HTTP headers are already written to the client browser. Any HTTP header modifications must be made before writing page content)

---- Min logout-kode ----
<%
' *** Logout the current user.
MM_Logout = CStr(Request.ServerVariables("URL")) & "?MM_Logoutnow=1"
If (CStr(Request("MM_Logoutnow")) = "1") Then
  Session.Contents.Remove("MM_Username")
  Session.Contents.Remove("MM_UserAuthorization")
  MM_logoutRedirectPage = "default.asp"
  ' redirect with URL parameters (remove the "MM_Logoutnow" query param).
  if (MM_logoutRedirectPage = "") Then MM_logoutRedirectPage = CStr(Request.ServerVariables("URL"))
  If (InStr(1, UC_redirectPage, "?", vbTextCompare) = 0 And Request.QueryString <> "") Then
    MM_newQS = "?"
    For Each Item In Request.QueryString
      If (Item <> "MM_Logoutnow") Then
        If (Len(MM_newQS) > 1) Then MM_newQS = MM_newQS & "&"
        MM_newQS = MM_newQS & Item & "=" & Server.URLencode(Request.QueryString(Item))
      End If
    Next
    if (Len(MM_newQS) > 1) Then MM_logoutRedirectPage = MM_logoutRedirectPage & MM_newQS
  End If
  Response.Redirect(MM_logoutRedirectPage)
End If
%>