Add lookup field in a form

I know that the Vehicle Log form has two readonly fields: Make and Model. When I choose a License Plate, the Make and the Model fields are retrieved. How I can add a similar lookup filed for the Employee? I need to see the full name into the form and also into the reports. What is the method to get a lookup field?
Thank you

Hi @skycult,

in your custom doctype, you have a link field to the Employee, like

Employee | Link | employee | Employee

Add a new field, e.g.

Full Name | Data | full_name | employee.full_name

where the last column is Options.

Hope this helps.

Thank you @lasalesi: it works like a charm!
All the best!