Auto-populating values based on a lookup field in Dynamics CRM

Hello,

I have 3 fields in Account entity: Contact Name, Contact Email and Contact Phone Number.

I need to achieve this: When Contact name is selected (Lookup), Contact Email and Contact Phone number should be auto-populated.

I tried doing this by workflow but couldn't get the results. Should Contact Email and Phone number be lookup fields as well or they can be just single line of text?

I know it is possible by adding javascript on onChange event but I am not sure how to retrieve data from Contact entity.

Any suggestions?

Thank you.