Update ticket field and then update contact ticket

Update ticket field and then update contact ticket

I have one custom field "Enquiry Product" on Ticket module and Same "Enquiry Product" field on Contact module.
I want to, after the Ticket module "Enquiry Product" Value set, then the contact module of  "Enquiry Product" file has same value automatically. 
I don't want to manual to make it.
Thank you.