All the modern browsers come with built-in support for JavaScript. Frequently, you may need to enable or disable this support manually. This chapter explains the procedure of enabling and disabling JavaScript support in your browsers: Internet Explorer, Firefox, chrome, and Opera.
Here are simple steps to turn on or turn off JavaScript in your Internet Explorer −
Follow Tools → Internet Options from the menu.
Select Security tab from the dialog box.
Click the Custom Level button.
Scroll down till you find Scripting option.
Select Enable radio button under Active scripting.
Finally click OK and come out
To disable JavaScript support in your Internet Explorer, you need to select Disable radio button under Active scripting.
Here are the steps to turn on or turn off JavaScript in Firefox −
Open a new tab → type about: config in the address bar.
Then you will find the warning dialog. Select I’ll be careful, I promise!
Then you will find the list of configure options in the browser.
In the search bar, type javascript.enabled.
There you will find the option to enable or disable javascript by right-clicking on the value of that option → select toggle.
If javascript.enabled is true; it converts to false upon clicking toogle. If javascript is disabled; it gets enabled upon clicking toggle.
Here are the steps to turn on or turn off JavaScript in Chrome −
Click the Chrome menu at the top right hand corner of your browser.
Select Settings.
Click Show advanced settings at the end of the page.
Under the Privacy section, click the Content settings button.
In the "Javascript" section, select "Do not allow any site to run JavaScript" or "Allow all sites to run JavaScript (recommended)".
Here are the steps to turn on or turn off JavaScript in Opera −
Follow Tools → Preferences from the menu.
Select Advanced option from the dialog box.
Select Content from the listed items.
Select Enable JavaScript checkbox.
Finally click OK and come out.
To disable JavaScript support in your Opera, you should not select the Enable JavaScript checkbox.
If you have to do something important using JavaScript, then you can display a warning message to the user using <noscript> tags.
You can add a noscript block immediately after the script block as follows −
<html> <body> <script language = "javascript" type = "text/javascript"> <!-- document.write("Hello World!") //--> </script> <noscript> Sorry...JavaScript is needed to go ahead. </noscript> </body> </html>
Now, if the user's browser does not support JavaScript or JavaScript is not enabled, then the message from </noscript> will be displayed on the screen.