I have created custom visualforce page for the liveagent chat window and also done the setup.
Setup > Customize > Live Agent > Chat Buttons > Edit > Custom Chat Window.

But the custom chat page works only if do NOT specify agent ID?
For example :
liveagent.startChat(button); launches chat with custom page, but liveagent.startChat(button, agent); launches chat with default page

Please help me.

I am having trouble finding any documentation on:

 

1.  What is the difference between Abstract and Virtual classes (they seem to be the exact same to me)

 

2. What are some scenarios for using Abstract or Virtual classes (wrapper classes comes to mind but are these the right thing to use?)

 

3.  When would you use an Interface instead of an Abstract or Virtual?  I read they are only suppose to be signatures but I saw an example that had a method with code in it too..