For the browser to execute the statement, it must be placed inside a
<script> element. This element describes which section of the HTML code contains executable code, and will be described in further detail later.
<script> element should then be nested inside the
This basic hello world program can then be used as a starting point for any new programs that you need to create.
Exercise 1-1 
Copy and paste the basic program in a file, save it on your hard disk as "exercise 1-1.html". You can run it in two ways:
- By going to the file with a file manager, and opening it using a web browser (e.g. in Windows Explorer it is done with a double click)
- By starting your browser, and then opening the file from the menu. For Firefox, that would be: Choose File in the menu, then Open File, then select the file.
Exercise 1-2 
Save the file above as "exercise 1-2.html". Replace the double quotes in the line alert("Hello World!"); with single quotes, so it reads alert('Hello World!'); and save the result. If you open this file in the browser, what happens?