I've added an "email submit button" to my form... Is there a way to reference data in two text fields on my form and have it appear on the subject line of the email ?

I've added an "email submit button" to my form... Is there a way to reference data in two text fields on my form and have it appear on the subject line of the email ?  My form has a first and last name field and I want that to appear along with some additional text around it.