Find Port Number Using T-SQL

DECLARE @portNumber varchar(20), @key varchar(100)
if charindex('\',@@servername,0) <>0
begin
           set @key = 'SOFTWARE\MICROSOFT\Microsoft SQL Server\' +@@servicename+
                                                                                           '\MSSQLServer\Supersocketnetlib\TCP'
end
else
begin
          set @key = 'SOFTWARE\MICROSOFT\MSSQLServer\MSSQLServer\Supersocketnetlib\TCP'
end

EXEC master..xp_regread @rootkey='HKEY_LOCAL_MACHINE', @key=@key, @value_name='Tcpport', @value=@portNumber OUTPUT

SELECT 'Server Name: '+@@servername + ' Port Number:'+convert(varchar(10),@portNumber)