Dynamically hide or display custom field on contact form

We are using Dynamics CRM 2013

I would like to have a custom field on a contact record, which is either visible or hidden depending on if another custom field dropdown has a particular value selected.

Is there a way to dynamically hide or display the custom field like this?

I have had a look in the properties of the Contacts form. But I am wondering do I need to write some custom code to do this? And if so are there any examples of this particular action (hiding or displaying the custom field on the form).

Thanks.