How to configure periodicity in amibroker

Hi..

How to set periodicity to the customized interval.I am looking to set 5 minutes.But that is not available in the drop down.
Please find the image.
Time%20interval

Read the manual http://www.amibroker.com/guide/h_charting.html, it says:

" Please note that intraday intervals are disabled if your database is in end-of-day mode. Intraday modes are available only for databases that have "Base time interval" in File->Database Settings set to anything less than end-of-day. If you for example set "Base time interval" in File->Database Settings to 5-minute, all chart periodicities from 5-minutes up will be enabled."

Entire tutorial section is must-read.