HTML Script Tags
HTML Script Tag
You can write your Event Handlers using any of the scripting language and then you can trigger those functions using HTML attributes.
If you have to use a single script functionality among many HTML pages then it is a good idea to keep that function in a single script file and then include this file in all the HTML pages. You can incluse a style sheet file into HTML document using <script> element. Below is an example.
<title> internal script></title>
This will produce following result :