i suppose you can use an existing form field for example : "address 3" or any other one for your own usage ... & just open vicidial.php & change its name to suite the purpose you want to give it & try again.
There could be all sorts of reasons that this is not working, the Javascript code is very complex. Do you see anything in the Firefox error console after trying to hangup?
Yes will do... Ill give it step by step on how to add additional forms. Give me until next week, as I am too busy to teach the employee on how to work on vicidial.
Adding custom fields to the vicidial agent interface is on the roadmap for 2.2.0. We have thought of a method for doing this that will allow for great flexibility while not compromising speed and a high volume of records in the custom fields(Like the problem with the Vtiger custom field design).
No estimated completion date, but if it is sponsored it could be done in a couple weeks in SVN trunk.