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
What attribute makes a radio button or checkbox input selected?
checked="checked" selected="selected" disabled="disabled"
<input type="checkbox" name="a_name" value="value" checked="checked" />
What CSS value scales the background image to the largest size contained within the element?
repeat-x contain linear-gradient
#id {
  background:url("path_to_image.png");
  background-size:contain;
  background-repeat:no-repeat;
}
What operator is used to determine the rest of the division of two numbers?
% * /
var rest8_7 = 8 % 7;
alert(rest8_7);
Indicate the PHP function that rounds a number up to the next highest integer.
floor() ceil() abs()
$nr = ceil(3.5);
echo $nr;        // 4
Show a message if JavaScript disabled or Ad-Blocker

Last accessed pages

  1. New Form elements and attributes in HTML5 (4901)
  2. Defining classes with Methods that can be chained (913)
  3. Circle and Oval with CSS (6077)
  4. PHP Method Chaining (2625)
  5. Add and Remove HTML elements and Content with jQuery (28105)

Popular pages this month

  1. Courses Web: PHP-MySQL JavaScript Node.js Ajax HTML CSS (84)
  2. Read Excel file data in PHP - PhpExcelReader (65)
  3. PHP-MySQL free course, online tutorials PHP MySQL code (54)
  4. SHA1 Encrypt data in JavaScript (52)
  5. Create simple Website with PHP (47)