if you do not want to have separate login page and handle redirects(you want login module on home page which is visible depending on the current user) you should register login module control in your page markup and handle the visibility logic in the code behind(.cs file).
If you are using existing MonoX page you should add the code behind file(that means extend the existing page/control) and handle visibility logic there. An example "OnPreRender" page event.
Source code edition allows you to take advantage of the .cs files. Free version does not contain .cs files, but you can still extend the existing functionality. Click here
for an example on how to do it.