SQL Scalar-Valued Function MSSQL for Business Logics

CREATE FUNCTION dbo.StripWWWandCom (@input VARCHAR(250))
RETURNS VARCHAR(250)
AS BEGIN
    DECLARE @Work VARCHAR(250)

    SET @Work = @Input

    SET @Work = REPLACE(@Work, 'www.', '')
    SET @Work = REPLACE(@Work, '.com', '')

    RETURN @work
END

and then use:

SELECT ID, dbo.StripWWWandCom (WebsiteName)
FROM dbo.YourTable .....

CREATE FUNCTION dbo.RAGconvertion (@input NVARCHAR(250))
RETURNS Nvarchar(250)
AS BEGIN
    DECLARE @RAGint INT --Nvarchar(250)

    SET @RAGint = 
 CASE @Input
  WHEN 'Green' THEN '3'
  WHEN 'Amber' THEN '2'
  WHEN 'Red' THEN '1'
  WHEN '[Please Choose]' THEN '0'
  ELSE '0'
 END
    --SET @Work = REPLACE(@Work, 'www.', '')
    --SET @Work = REPLACE(@Work, '.com', '')

    RETURN @RAGint
END