Dial from CRM to PBX

How can I dial through my web based CRM developed in PHP by clicking on phone number. If there is any built in API for it or if i can write myself as i am PHP developer and need its guide. I am using Asterisk server.

Go through wiki.asterisk.org/wiki/pages/vi … Id=4817239
I assumed you have a basic knowledge of Asterisk, otherwise
asteriskdocs.org/en/3rd_Edit … index.html
wiki.asterisk.org/wiki/display/ … he+Project
are good places to start with.

–Satish Barot