Code:
<html>
<head>
</head>
<body>
<script type="text/javascript">
document.write("Hello World!")
</script>
</body>
</html>
And it produces this output:

Code:
Hello World!
To insert a script in an HTML document, use the <script> tag. Use the type attribute to define the scripting language.

Code:
<script type="text/javascript">
Then comes the JavaScript: In JavaScript the command for writing some text on a page is document.write:

Code:
document.write("Hello World!")
The script ends:

Code:
</script>
Inserting Text With HTML Formatting

Write text with formatting
How to format the text on your page with HTML tags

Code:
<html>
<body>
<script type="text/javascript">
document.write("<h1>Hello World!</h1>")
</script>
</body>
</html>

Ending Statements with a Semicolon?


With the traditional programming languages C++ and Java, each code statement has to end with a semicolon.

Many programmers continue this habit when writing JavaScript, but in general, semicolons are optional and are required only if you want to put more than one statement on a single line.