Dogma, have a look in the en-route section of Jeppesen manual AFR1. There you should find the exact format and importantly when to make calls on 126.9 - making the call when you are actually at the intersection could be closing the stable door after nobby has bolted...straight through your windshields.
Also, the format is printed on the high and high/low en-route charts to assist with making these transmissions.
The en-route section also details the area of applicablity of the IATA In-flight Broadcast Procedure (IFBP).