I've used fiddler2 in the past to identify field names and buttons on a web page. Using this information I've been able to write automated scripts using jmeter or canoo webtest.
I've been testing a new website and using fiddler2 I was able to retrieve the field names for the login page. However once logged in I am unable to retrieve any field names for the data entry forms. Without these field names I will not be able to write any automated scripts.