BLF with "auto-pickup"

I am running Asterisk v1.4.x and have 2 Aastra 9134i phones. I would like to do the following and am looking for guidance:
[ul]On each phone, have a button that lights up when the other phone is in use. I know this can be done with BLF and SIP presence.
When a user presses the button associated with the lit up light, they are automatically “bridged” on to the conversation. This is the part I need help with.[/ul]
Is the above possible?