src variable - using an external JavaScript

• JavaScript can also be placed in external files. External JavaScript files often contain code to be used on several different web pages. External JavaScript files have the file extension .js.
• You can use attribute src to include an external file containing JavaScript code:<script language="JavaScript" src="hello.js"></script>
• For example, shown below is the code of the external file hello.js
       document.write("Hello World!")

Note: External script cannot contain the <script> and </script> tags!