Hello.
Your question is quite vague. What specifically are you trying to accomplish and what are you have trouble with that makes you unable to write your code. Are you writing for a web site or a pc program? Do you have a data base that you are keeping user information in or are you banking on using window authentication? We can help you if you provide more specifics. In general you can probably find help by searching for articles.
Here is what I found when I search for articles about logins.[
^] If you have more specific information you may be able to narrow the search.
Hope this helps.
Submit an article or tip