CASE in WHERE clause?

I would like to select customers from my database depending on some criteria that the users choose - such as area code, company size etc. Since i have about 15 criteria and the users want to be able to choose many criteria for one selection i can't make one procedure for each criteria - i would end up with about a hundred procedures. I want to let the users choose what criteria to search on and have ONE single select statement that return the customers. Something like:

select name, address, city etc
from customer
where if users want to see customers of a certain type then type = @.myInParameterForType
and if users want to see customers from a certain area then area = @.myInParameterForArea

is this possible? sorry if i made you all confused...my english is not perfect! Thanks in advance!Yes, you may use CASE in where|||one easy (but not very performant) way is to build your "where" clause in your application (ie:web form ) and send it to your sp:
------------------------
CREATE PROCEDURE mySP

(
@.WhereClause varchar(4000)
)

AS
Declare @.SQL varchar(6000)

begin

set @.SQL = 'SELECT field1, field2 ... from myTable where ' + @.WhereClause + ' ORDER BY someID'

end

EXEC (@.SQL)

RETURN

GO
------------------------

when you have many optional parameter it is very conveniant