Find SQL Server Port

DECLARE @InstanceName nvarchar(50)
DECLARE @value VARCHAR(100)
DECLARE @RegKey_InstanceName nvarchar(500)
DECLARE @RegKey nvarchar(500)

SET @InstanceName=CONVERT(nVARCHAR,isnull(SERVERPROPERTY('INSTANCENAME'),'MSSQLSERVER'))

--For SQL Server 2000
if(SELECT Convert(varchar(1),(SERVERPROPERTY('ProductVersion'))))=8
BEGIN
if @InstanceName='MSSQLSERVER'
Begin
SET @RegKey='SOFTWARE\Microsoft\'+@InstanceName+'\MSSQLServer\SuperSocketNetLib\TCP\'
END
ELSE
BEGIN
SET @RegKey='SOFTWARE\Microsoft\Microsoft SQL Server\'+@InstanceName+'\MSSQLServer\SuperSocketNetLib\TCP\'
END

EXECUTE xp_regread
  @rootkey = 'HKEY_LOCAL_MACHINE',
  @key = @RegKey,
  @value_name = 'TcpPort',
  @value = @value OUTPUT

Select @@SERVERNAME as ServerName,@value as PortNumber
END

--For SQL Server 2005 and up
if(SELECT Convert(varchar(1),(SERVERPROPERTY('ProductVersion'))))<>8
BEGIN
SET @RegKey_InstanceName='SOFTWARE\Microsoft\Microsoft SQL Server\Instance Names\SQL'

EXECUTE xp_regread
  @rootkey = 'HKEY_LOCAL_MACHINE',
  @key = @RegKey_InstanceName,
  @value_name = @InstanceName,
  @value = @value OUTPUT

SET @RegKey='SOFTWARE\Microsoft\Microsoft SQL Server\'+@value+'\MSSQLServer\SuperSocketNetLib\TCP\IPAll'

EXECUTE xp_regread
  @rootkey = 'HKEY_LOCAL_MACHINE',
  @key = @RegKey,
  @value_name = 'TcpPort',
  @value = @value OUTPUT

Select @@SERVERNAME as ServerName,@value as PortNumber
END

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
OR


DECLARE @InstName VARCHAR(16)

DECLARE @RegLoc VARCHAR(100)

SELECT @InstName = @@SERVICENAME

IF @InstName = 'MSSQLSERVER'
  BEGIN
    SET @RegLoc='Software\Microsoft\MSSQLServer\MSSQLServer\SuperSocketNetLib\Tcp\'
  END
 ELSE
  BEGIN
   SET @RegLoc='Software\Microsoft\Microsoft SQL Server\' + @InstName + '\MSSQLServer\SuperSocketNetLib\Tcp\'
  END

EXEC [master].[dbo].[xp_regread] 'HKEY_LOCAL_MACHINE', @RegLoc, 'tcpPort'