I am not really sure if should proceed from there. If your master page has login form on it, it means that all related content pages will also do the login. In principle, this is possible — it might look like in CodeProject. But are you sure you need it?
Anyway, please see this tutorial: http://www.asp.net/web-forms/tutorials/master-pages
Your code sample does not look like an integral clause, so I cannot say anything. Probably, you simply failed to format the code properly.