Check If Certain Text Was Outputted To The Screen Php

How would I check if certain text was outputted to the screen using PHP? For example, I have this code:

Solution 1:

The only thing I can think of is setting a cookie:

<scripttype="text/javascript">document.cookie = "jsEnabled=true";
</script>

Then, you can do a simple check in PHP:

<?phpif (isset($_COOKIE['jsEnabled'])) {
    // Javascript is enabled!
} else {
    // Javascript is not enabled!
}