CREATE PROCEDURE [LoneUser]
--INPUT
@DBName     nvarchar(50),
@UserName   nvarchar(50)
AS
    Exec sp_configure 'allow updates','1'
    RECONFIGURE WITH OVERRIDE
   
    Declare @ExecStr nvarchar(4000)
   
    Select @ExecStr = ' Declare @b varbinary(85) '
  + ' Use Master'
  + ' Select @b = sid From syslogins Where Name = ''' + @UserName + ''''
  + ' Use ' + @DBName
  + ' Update sysusers Set sid = @b Where name = ''' + @UserName + ''''

    --Print @ExecStr
    Exec(@ExecStr)

    Exec sp_configure 'allow updates','0'
    RECONFIGURE WITH OVERRIDE