Concatenate

Concatenate

I want to be able to create a lookup field on my form Ticket called "Name" that will concatenate two fields from my Customer form with first_name and last_name.
 
Can this be done?
 
I've tried variations of the following:
 
values = Customer.first_name+" "+last_name
 
or
 
values = Customer.first_name && last_name
 
etc, etc, etc....
 
No luck.  Can anyone help?