Screen pop using AMI manager

What is the best event(s) to key in on to be able to write a screen pop application when looking through the ouput of the AMI? Thanks.

simple

at an appropriate juncture in the dialplan set a var like this:

same=> n,Set(SCREENPOP=${CALLERID(num)}:${CALLERID(name)}:${EXTEN})

then retrieve VARSET Event and parse data.

Voila!