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't do it with just CSS, but you can do it with Javascript, and (optionally) [jQuery](http://jquery.com).

If you want to do it without jQuery:

```
<script>
    window.onload = function() {
        var anchors = document.getElementsByTagName('a');
        for(var i = 0; i < anchors.length; i++) {
            var anchor = anchors[i];
            anchor.onclick = function() {
                alert('ho ho ho');
            }
        }
    }
</script>

```

And to do it without jQuery, and only on a specific class (ex: `hohoho`):

```
<script>
    window.onload = function() {
        var anchors = document.getElementsByTagName('a');
        for(var i = 0; i < anchors.length; i++) {
            var anchor = anchors[i];
            if(/\bhohoho\b/).match(anchor.className)) {
                anchor.onclick = function() {
                    alert('ho ho ho');
                }
            }
        }
    }
</script>

```

If you are okay with using [jQuery](http://jquery.com), then you can do this for all anchors:

```
<script>
    $(document).ready(function() {
        $('a').click(function() {
            alert('ho ho ho');
        });
    });
</script>

```

And this jQuery snippet to only apply it to anchors with a specific class:

```
<script>
    $(document).ready(function() {
        $('a.hohoho').click(function() {
            alert('ho ho ho');
        });
    });
</script>

```
Here is my solution through CSS, It does not use any JavaScript at all

HTML:

```
<a href="#openModal">Open Modal</a>

<div id="openModal" class="modalDialog">
        <div>   <a href="#close" title="Close" class="close">X</a>

                <h2>Modal Box</h2>

            <p>This is a sample modal box that can be created using the powers of CSS3.</p>
            <p>You could do a lot of things here like have a pop-up ad that shows when your website loads, or create a login/register form for users.</p>
        </div>
    </div>

```

CSS:

```
.modalDialog {
    position: fixed;
    font-family: Arial, Helvetica, sans-serif;
    top: 0;
    right: 0;
    bottom: 0;
    left: 0;
    background: rgba(0, 0, 0, 0.8);
    z-index: 99999;
    opacity:0;
    -webkit-transition: opacity 400ms ease-in;
    -moz-transition: opacity 400ms ease-in;
    transition: opacity 400ms ease-in;
    pointer-events: none;
}
.modalDialog:target {
    opacity:1;
    pointer-events: auto;
}
.modalDialog > div {
    width: 400px;
    position: relative;
    margin: 10% auto;
    padding: 5px 20px 13px 20px;
    border-radius: 10px;
    background: #fff;
    background: -moz-linear-gradient(#fff, #999);
    background: -webkit-linear-gradient(#fff, #999);
    background: -o-linear-gradient(#fff, #999);
}
.close {
    background: #606061;
    color: #FFFFFF;
    line-height: 25px;
    position: absolute;
    right: -12px;
    text-align: center;
    top: -10px;
    width: 24px;
    text-decoration: none;
    font-weight: bold;
    -webkit-border-radius: 12px;
    -moz-border-radius: 12px;
    border-radius: 12px;
    -moz-box-shadow: 1px 1px 3px #000;
    -webkit-box-shadow: 1px 1px 3px #000;
    box-shadow: 1px 1px 3px #000;
}
.close:hover {
    background: #00d9ff;
}

```

[CSS alert No JavaScript Just pure HTML and CSS](http://jsfiddle.net/a2t3a079/)

I believe that it will do the trick for you as it has for me