Fetch contact details (phone, mobile, email) and update custom fields in a task as a Task Field Validation activity.

Fetch contact details (phone, mobile, email) and update custom fields in a task as a Task Field Validation activity.

Hi Zoho Gurus,

We have added several fields to tasks to help streamline our sales and customer care operations.

I want to create a function that is triggered during field validation on a Task entry.  The function will fetch the associated contact record (using the Task's Contact) and fill in three custom fields on the Task for...
customer email -> task email
customer mobile -> task mobile
customer phone -> task phone

I cannot figure out the easiest way to do this via Deluge script.

Can someone please provide some sample code.

My key areas are:
1. how to get the contact id from the record being validated
2. how to fetch the associated contact and place the contents into a map variable, using the contact id 
3. how to update the three fields - email, mobile and phone - on the Task being validated.

Best regards,
Joe