Drop a phone call

Hi,
I´m a new user of B4A and I want to say that it is very good.

First, sorry for my English, I´m from México and I don´t speak or write English very well, so I'll try to explain better I can.

¿There are some way to drop a phone call?

For example:
When I use StartActivity(P.Call("012345678")) one phone call is started, now I want to do something like P.DropCall to "kill" the current phone call.

¿How can I do that?

Thanks

Alejandro