Add scripts to HTML pages to make them more dynamic and
interactive.
Insert a Script into HTML Page
A script in HTML is defined with the <script> tag. Note that you will
have to use the type attribute to specify the scripting language.
<html>
<head>
</head>
<body>
<script type="text/javascript">
document.write("Hello World!")
</script>
</body>
</html>
|
The script above will produce this output:
Hello World!
How to Handle Older Browsers
A browser that does not recognize the <script> tag at all, will display
the <script> tag's content as text on the page. To prevent the browser from
doing this, you should hide the script in comment tags. An old browser (that does not
recognize the <script> tag) will ignore the comment and it will not write
the tag's content on the page, while a new browser will understand that the
script should be executed, even if it is surrounded by comment tags.
Example
JavaScript:
<script type="text/javascript">
<!--
document.write("Hello World!")
//-->
</script>
VBScript:
<script type="text/vbscript">
<!--
document.write("Hello World!")
'-->
</script>
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The <noscript> Tag
In addition to hiding the script inside a comment, you can also add a <noscript>
tag.
The <noscript> tag is used to define an alternate text if a
script is NOT executed. This tag is used for browsers that recognize the
<script> tag, but do not support the script inside, so these browsers will
display the text inside the <noscript> tag instead. However, if a browser supports
the script inside the <script> tag it will ignore the <noscript>
tag.
Example
JavaScript:
<script type="text/javascript">
<!--
document.write("Hello World!")
//-->
</script>
<noscript>Your browser does not support
JavaScript!</noscript>
VBScript:
<script type="text/vbscript">
<!--
document.write("Hello World!")
'-->
</script>
<noscript>Your browser does not support VBScript!</noscript>
|
Script Tags
| Tag |
Description |
| <script> |
Defines a script |
| <noscript> |
Defines an alternate text if the script is not executed |
| <object> |
Defines an embedded object |
| <param> |
Defines run-time settings (parameters) for an object |
| <applet> |
Deprecated. Use <object> instead |
