asterisk users - Sep 2010 - Commands needed via AMI to find callerid of inbound call to extension

Hi all,

Can anyone help with the logic of which commands to use to say:

1. Extension is 600
2. See if has an ongoing call
3. Check if inbound or outbound to the extension
4. Find callerid of inbound call

Been reading http://www.voip-info.org/wiki/view/Asterisk+manager+API

Using latest 1.6.

Thanks.