function for sql

ALTER function [dbo].[GetRomanDate]
(
@Date datetime
)
returns varchar(20)
Begin
Declare @RomanDate varchar(20)
select @RomanDate=Convert(varchar(8),@Date,4)+ ' - '+ Convert(varchar(8),@Date,108)
return @RomanDate
End
--------------------------------
ALTER function [dbo].[GetperiodTitle](@Periodid int)
returns varchar(500)
as
begin
declare @title varchar(500)
set @title=(select 'Tema: ' + Periodname as periodname from utbfperiod where bfperiodid=@Periodid)
return @title

End
-------------------------------
ALTER function [dbo].[getCourseString]
(
@kindergarden varchar(100),@city varchar(100)
)
returns varchar(200)
begin
declare @TempString varchar(250)
set @TempString=''
if(@kindergarden=''and @city='')
begin
set @TempString=''
end
else
if(@kindergarden=''and @city <> '')
begin
set @TempString=@city
end
else if(@kindergarden <> '' and @city='')
begin
set @TempString=@kindergarden
end
else if(@kindergarden <>''and @city <> '')
begin
set @TempString=@kindergarden +', '+@city
end



return @TempString
end