Problem in form design! Help me!

Problem in form design! Help me!

In my application i have two tables: 1) table 'Contacts' with fields FirstName, LastName 2) table'Tickets' with fields Contact, Date, TypeOfTicket

Problem: in the table Tickets the field Contact takes data from the table Contacts but i can only see only one field in the combobox...it would be nice to see for example.... LastName & " " FirstName, not only LastName