Doubt in Sql Query

Question

hi!
 
 i am create table like
create table user1(id int,firstname varchar(50),Lastname varchar(50), Fullname as (lastname + firstname))
table is executed. but i am write query to select value this time it shows empty column i write statement below. how to solve this. and i am goto objectexplorer and select modify table of user1. in that it shows no data type for Fullname column. what is default data type of sql server.
select id from user1 where Fullname = 'K.Ajay'
Thanks.