Installing .Mac in order to use isync

[Jennih]

I have recently inherited a fairly old mac, and would like to be able to sync it with another mac so that I can share a colleauge's I-cal and we can both edit it. I have a mac account but I-Sync says that this is not configured. I used the help menu and on the page 'Setting your preferences to access .Mac' when I click 'Open .Mac preferences for me' I get the message: 'The item cannot be opened. It may be disabled or not installed.'

Is there something I can download / install which will solve this problem?

Any help much appreciated - in dummy terms if possible as I'm not very mac-experienced!


Thanks