Setting callerid when originating a call through manager api

Asterisk Asterisk Support
1

I am trying to iriginate a call and set teh caller id, but the callerid never gets set. here is what i am sending:
fputs($socket, “Action: Originate\r\n”);
fputs($socket, “Channel: SIP/xxxxxxxxxxx@provider\r\n”);
fputs($socket, “Context: internal\r\n”);
fputs($socket, “Priority: 1\r\n”);
fputs($socket, “Callerid: 7605551212\r\n”);
fputs($socket, “Exten: 80\r\n”);
fputs($socket, “Async: yes\r\n\r\n”);

note that info has been changed to protect privacy. But the callerid calue is not sent. any ideas?