Most contemporary web designers do not use the workarounds here unless they absolutely know that they have to support older browsers. However, you might want to use them. At the very least, it's important that you see these techniques in action so you'll recognize them when viewing HTML from other sources.
Hiding Scripts from Older Browsers
To avoid this, many people got into the habit of "commenting out" their scriptsin other words, using comment syntax to prevent the script from being displayed (see Example 3-11).
Example 3-11. Hiding a script with comments
Using the noscript Element
If you'd like to add some text so supporting browsers will display a message regarding script support, you can do so using the noscript element (see Example 3-12).
Example 3-12. Using the noscript element
Browsers that support scripting and do not have scripting disabled will not see the contents of the noscript element.
Finding Scripts Online