program DiscoverCard;

procedure OnDocumentComplete(URL : string);
begin
  if (IsPartOf('home.shtml', URL)) or
     (IsPartOf('main.shtml', URL)) then 
    begin
      Fill('userID', GetParam('dcardL'));    // define dcarL in Parameters
      Fill('password', GetParam('dcardP'));  // define dcarP in Parameters
      ClickImageButton('Log In');
    end;  
end;

begin
  Navigate('http://www.discovercard.com/');
end.