CLI Auto Script Example Needed

Hi

Please can someone advise how I can write a script which I can use with CLI Auto Script feature on version 5.4

http://help.fortinet.com/fos50hlp/54/Content/FortiOS/fortigate-system-administration-54/Advanced/CLI%20Scripts.htm

I am trying to write a script that will run every 30 mins and collect the output & save in a file.

Your help would be much appreciated.