HTML <script> Tag
The <script> element can contain script statements, or point to an external script file through the src attribute.
The following script will output “Hello World!” to the browser:
<script> document.write("Hello World!"); </script>
The <noscript> tag provides alternative content when scripts cannot be used, such as when scripts are disabled in the browser, or when the browser does not support client-side scripting.
The <noscript> element can contain all the elements that can be found in the body element of a normal HTML page.
The content in the <noscript> element will only be displayed when the browser does not support scripting or scripting is disabled:
document.write (" <p>This is a paragraph.</p> ");
<button type="button" onclick="myFunction()"> Click Me </button>