[Asterisk-Users] Re: phone line "roaming"

[Pavel Jezek]

thanks for idea, but this is not exactly what I need, assume: 
one employee working in office (open-space "cubes"), when this employee leave the work, on the same place come another employee
so that, I can't ring both lines and can't use bluetooth device :(

I thing to do some "login" to phone & asterisk and "download" appropriate extension/phone line 
according to e.g. username/login id, but how to configure/implement?
(we use cisco7940 & 7912)
PJ