Embedding PHP code into html is powerful rule that most programmers use. However, you should configure your server in order to get the benefits of this feature. It will only work if your Apache server has PHP enabled (how to test php support in a Apache server) and .htaccess enabled. In the root directory of your html files create a file named .htaccess (DOThtaccess).
Open the file in your favorite editor (I use notepad) and add the following lines: