I want to be able to create a deal in Zoho CRM and a Meeting be created so that it adds to my calendar, however when I edit the same deal, I want it to edit the meeting, not create a new meeting!  Everytime I edit a deal, It creates a new meeting so I end up with lots of meetings with the same client.

Also, I have added to deals some new fields - Start date / time and end date / time. The meeting is created at the correct start date / time but I can't get it to last until the end date / time.

I have created this as a simple workflow but obviously I am missing something.  Help!