How to change default port in wamp server

If our computer have only wampserver is okay but If start using Microsoft product such as Visual Studio, Visual Webdeveloper or we install IIS the port 80 of wampserver will be used by those products. sometimes we install some software that can take the port 80 of wampserver too.
If wampserver port 80 is used we can solve this problem as below:

1. Click on Wampserver
 

2. Click on Apache

3. Click on httpd.conf

4. find word "Listen 12.34.56.78:80"

5. type "#" infront of  "Listen 12.34.56.78:80"

6. type "Listen 81" under "# Listen 12.34.56.78:80

7. Save httpd.conf file ( ctrl + s) and close httpd.conf file

8. Click on Wamp icon and Click on "Restart All Services"

Now it is done.