Concatenating Fields In SQL

I am using SQL server 2000 and trying to do a concatenation of firstname,middle-initial and lastname.

SELECT first_name+('mid_ini'=
case
when middle_init is null then ''
when middle_init ='' then ''
else middle_init
end)+nsl_last_name
FROM tbl_names

How is it possible to use the CASE condition along with concatenating the fields. Is this possible?

I would like my result to be "Bob J Sam".

and if there is no middle initial it should be blank or when its null it should be blank.

I know you can separate and get the results with the CASE statement,but is this feasible when you want to concatenate?

Thank you