Javascript Course

The code presented in this page can be used to detect if the visitor has an Ad-Blocker that blocks Ads in page, and to display a friendly message to visitor when the JavaScript is disabled or Ads are blocked.
The script was tested with Adblock Plus.

Script code

- Just add the following HTML /CSS /JS code in the pages of your website.

<style>
#jsad_notify{
background:#f8f800;
border:2px solid #0000be;
color:#ee0000;
font-size:20px;
font-weight:700;
margin:0;
padding:2px;
position:fixed;
top:40px;left:1%;right:1%;
text-align:center;
max-width:98vw;
}
</style>

<div id='jsad_notify'>
Parts of this site works with JavaScript enabled; and without AdBlock.<br>
Please consider supporting us by disabling your Ad-Blocker on this website.
</div>

<script>
//if JavaScript enabled, it hides #jsad_notify
var jsad_notify = document.querySelector('#jsad_notify');
jsad_notify.style.display ='none';

//adds a child-element in page which usually is blocked by Ad-Blocker
var test_adb = document.createElement('div');
test_adb.innerHTML ='&nbsp;';
test_adb.className ='adsbox';
document.body.appendChild(test_adb);
window.setTimeout(function(){
 //if Ads blocked it shows the message, else it removes the #jsad_notify
 if(test_adb.offsetHeight ===0) jsad_notify.style.display ='block';
 else jsad_notify.outerHTML ='';

 document.body.removeChild(test_adb); //removes test_adb elm.
}, 700);
</script>

To change the position and design of the message, edit the CSS properties of the #jsad_notify element.

Daily Test with Code Example

HTML
CSS
JavaScript
PHP-MySQL
Which tag renders as emphasized text, displaying the text oblique?
<strong> <pre> <em>
<p>Web development courses: <em>CoursesWeb.net</em></p>
Which CSS property defines the space between the element border and its content?
margin padding position
h3 {
  padding: 2px 0.2em;
}
Click on the method which returns the first element that matches a specified group of selectors.
getElementsByName() querySelector() querySelectorAll()
// gets first Div with class="cls", and shows its content
var elm = document.querySelector("div.cls");
alert(elm.innerHTML);
Indicate the PHP variable that contains data from a form sent with method="post".
$_SESSION $_GET $_POST
if(isset($_POST["field"])) {
  echo $_POST["field"];
}
Show a message if JavaScript disabled or Ad-Blocker

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