insert two column information into one column

Question

hi
i take 3 columns in my sql server table i.e., firstname, lastname,Contactname
i insert firstname and lastname then contactname is (firstname+lastname).
how to write the query.
i tried like
insert into contacts values ('ajay','kalidindi','(firstname+lastname)') but here display contactname is firstname+lastname.
please give a reply. urgent
thanks.