w3schools
Search W3Schools :  
  
HOME HTML CSS XML JAVASCRIPT ASP PHP SQL MORE...   References Examples Forum About
VectorStock

JS Basic

JS HOME
JS Introduction
JS How To
JS Where To
JS Statements
JS Comments
JS Variables
JS Operators
JS Comparisons
JS If...Else
JS Switch
JS Popup Boxes
JS Functions
JS For Loop
JS While Loop
JS Break Loops
JS For...In
JS Events
JS Try...Catch
JS Throw
JS Special Text
JS Guidelines

JS Objects

JS Objects Intro
JS String
JS Date
JS Array
JS Boolean
JS Math
JS RegExp
JS HTML DOM

JS Advanced

JS Browser
JS Cookies
JS Validation
JS Animation
JS Image Maps
JS Timing
JS Create Object
JS Summary

JS Examples

JS Examples
JS Object Examples
JS DOM Examples
JS Quiz
JS Exam

JS References

JS Objects
JS HTML DOM

 

JavaScript Where To

previous next

JavaScripts in the body section will be executed WHILE the page loads.

JavaScripts in the head section will be executed when CALLED.


Where to Put the JavaScript

JavaScripts in a page will be executed immediately while the page loads into the browser. This is not always what we want. Sometimes we want to execute a script when a page loads, other times when a user triggers an event.

Scripts in <head>

Scripts to be executed when they are called, or when an event is triggered, go in the head section.

If you place a script in the head section, you will ensure that the script is loaded before anyone uses it.

Example

<html>
<head>
<script type="text/javascript">
function message()
{
alert("This alert box was called with the onload event");
}
</script>

</head>

<body onload="message()">
</body>
</html>

Try it yourself

Scripts in <body>

Scripts to be executed when the page loads go in the body section.

If you place a script in the body section, it generates the content of a page.

Example

<html>
<head>
</head>

<body>
<script type="text/javascript">
document.write("This message is written by JavaScript");
</script>

</body>

</html>

Try it yourself

Scripts in <head> and <body>

You can place an unlimited number of scripts in your document, so you can have scripts in both the body and the head section.

<html>
<head>
<script type="text/javascript">
....
</script>

</head>
<body>
<script type="text/javascript">
....
</script>

</body>


Using an External JavaScript

If you want to run the same JavaScript on several pages, without having to write the same script on every page, you can write a JavaScript in an external file.

Save the external JavaScript file with a .js file extension.

Note: The external script cannot contain the <script> tag!

To use the external script, point to the .js file in the "src" attribute of the <script> tag:

Example

<html>
<head>
<script type="text/javascript" src="xxx.js"></script>
</head>
<body>
</body>
</html>

Try it yourself

Note: Remember to place the script exactly where you normally would write the script!


previous next


729,913 sites built with Wix. Make your own

Click here to design a Stunning Flash Website for Free

Wix is a revolutionary web design tool that provides anyone with the possibility to create professional and beautiful websites for free.

With e-commerce features, search engine visibility and many more professional tools, Wix is the ultimate solution for creating a spectacular site while saving tons of money.



FUNC Travel
 
WEB HOSTING
Best Web Hosting
PHP MySQL Hosting
Top 10 Web Hosting
UK Reseller Hosting
Web Hosting
FREE Web Hosting
WEB BUILDING
Website Templates
Flash Templates
Website Builder
Internet Business Opportunity
Get a Freelancer
Download XML editor
FREE Flash Website
FREE Web Templates
FLIGHT TICKETS
Find the cheapest flight
to any destination now!
EDUCATION
US Web Design Schools
HTML Certification
JavaScript Certification
XML Certification
PHP Certification
ASP Certification
STATISTICS
Browser Statistics
Browser OS
Browser Display
W3Schools.com HOME | TOP | PRINT | FORUM | ABOUT
W3Schools is for training only. We do not warrant the correctness of its content. The risk from using it lies entirely with the user.
While using this site, you agree to have read and accepted our terms of use and privacy policy.
Copyright 1999-2009 by Refsnes Data. All Rights Reserved.