如何在一台机器上启动两个tomcat服务

    由于服务器上之前已安装Confluence, 它已自带了tomcat1.5。
而我想在服务器上再启用tomcat1.6，发布我的包。我用的是解压版。
在网上看了很多改端口的设置，在server.xml中将所有端口+1后，运行startup.bat，发现启动的还是tomcat1.5。
于是我修改了startup.bat，终于成功启动tomcat1.6了，以下红色标注的是修改的地方：

@echo off
rem Licensed to the Apache Software Foundation (ASF) under one or more
rem contributor license agreements.  See the NOTICE file distributed with
rem this work for additional information regarding copyright ownership.
rem The ASF licenses this file to You under the Apache License, Version 2.0
rem (the "License"); you may not use this file except in compliance with
rem the License.  You may obtain a copy of the License at
rem
rem     http://www.apache.org/licenses/LICENSE-2.0
rem
rem Unless required by applicable law or agreed to in writing, software
rem distributed under the License is distributed on an "AS IS" BASIS,
rem WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
rem See the License for the specific language governing permissions and
rem limitations under the License.

if "%OS%" == "Windows_NT" setlocal
rem ---------------------------------------------------------------------------
rem Start script for the CATALINA Server
rem
rem $Id: startup.bat 562770 2007-08-04 22:13:58Z markt $
rem ---------------------------------------------------------------------------

rem Guess CATALINA_HOME if not defined
set CURRENT_DIR=%cd%
rem# if not "%CATALINA_HOME%" == "" goto gotHome//
set CATALINA_HOME=%CURRENT_DIR%
set JAVA_HOME="C:\Sun\SDK\jdk"
if exist "%CATALINA_HOME%\bin\catalina.bat" goto okHome
cd ..
set CATALINA_HOME=%cd%
cd %CURRENT_DIR%
:gotHome
if exist "%CATALINA_HOME%\bin\catalina.bat" goto okHome
echo The CATALINA_HOME environment variable is not defined correctly
echo This environment variable is needed to run this program
goto end
:okHome

set EXECUTABLE=%CATALINA_HOME%\bin\catalina.bat

rem Check that target executable exists
if exist "%EXECUTABLE%" goto okExec
echo Cannot find %EXECUTABLE%
echo This file is needed to run this program
goto end
:okExec

rem Get remaining unshifted command line arguments and save them in the
set CMD_LINE_ARGS=
:setArgs
if ""%1""=="""" goto doneSetArgs
set CMD_LINE_ARGS=%CMD_LINE_ARGS% %1
shift
goto setArgs
:doneSetArgs

call "%EXECUTABLE%" start %CMD_LINE_ARGS%

:end