Question: Let's say I want that every time the user click any link an alert pops up that says "hohoho". 
Do I need to add `onclick="alert('hohoho')"` to every link or can I set this with CSS so that it works with every link?

Answer: 
You can do this by thinking of it a little bit differently. Detect when the body is clicked (`document.body.onclick` - i.e. anything on the page) and then check if the element clicked (`event.srcElement` / `e.target`) has a class and that that class name is the one you want:

```
document.body.onclick = function(e) {   //when the document body is clicked
    if (window.event) {
        e = event.srcElement;           //assign the element clicked to e (IE 6-8)
    }
    else {
        e = e.target;                   //assign the element clicked to e
    }

    if (e.className && e.className.indexOf('someclass') != -1) {
        //if the element has a class name, and that is 'someclass' then...
        alert('hohoho');
    }
}

```

Or a more concise version of the above:

```
document.body.onclick= function(e){
   e=window.event? event.srcElement: e.target;
   if(e.className && e.className.indexOf('someclass')!=-1)alert('hohoho');
}

```
Many 3rd party JavaScript libraries allow you to select all elements that have a CSS class of a particular name applied to them. Then you can iterate those elements and dynamically attach the handler.

There is no CSS-specific manner to do this.

In [JQuery](http://jquery.com/), you can do:

```
$(".myCssClass").click(function() { alert("hohoho"); });

```