The website of my school is designed by another person and I now setup a forum (I use phpBB) for my school.
My problem is that I do not know how to modify the website menu to set the link to go to the forum. The menu is simply designed by tool of dynamicdrive.com.
What I can do now?

It should be very easy to add another link to the menu, but I cannot be any more specific until I see the code for the website menu.

Here is the code: http://www.thptvietau.edu.vn/forum/upload/VAweb.zip
Thanks if you can help

If you need more file, please let me know. Thanks in advance

Since much of what you provided is in Vietnamese, it would really help if you only posted the code for the menu and not the entire code for the page. I might be able to decipher a few dozen lines of code...I will not attempt to decipher the entire contents of that ZIP file.

Just some file of menu now. Please help

I have checked files in ddtabmenufiles and ddlevelsfiles dir, but can not see where to modify. Where is {LeftMenu} in templates\main\index.html?