How to login to a webpage in Nessus and perform a SecTest?

I am trying to test a webpage using Nessus. I have tested all the stuff about the Server. But now I want to proceed by login to the webpage and test all possible pages behind the login form. But I couldn't achieve it. I gave all(text, password and hidden fields) the form fields' values including the ticket generated by Central Authentication System. But nothing happens. Either there isn't any security issue behind the login page ( :P ), or I couldn't login to the page (100% possibility :D ). For extra info:

These are login fields. ;)

username=
&password=
&lt=_c0C1F5872-F217-B20F-6D86-AA3AA1C1262E_kC7BEB4F7-5216-53EB-2F9A-7FDDFE01D145
&_eventId=submit
&submit=Login

Is there anyone who used Nessus and know how to solve this problem? And is there anyone who knows how to import Cookies to Nessus?

Thanks in advance. ;)