Creating My WYSIWYG Editor - JavaScript Strange Behaviour

Question

I'm working on my on Visual Text editor. It's working decently, preview works perfectly, and so does my JS appending. The HTML is this one:

<div class="wysiwyg">
    <div class="wystitle">What You See Is What You Get<br>Editor by ShowTime</div>
    <div class="wysmenu"><button class="wysbutton" onClick="addBold()">Bold</button><button class="wysbutton">Italic</button><button class="wysbutton">Underline</button><button class="wysbutton">Link</button><button class="wysbutton">Color</button><button class="wysbutton">Quote</button></</div>
    <textarea rows="9" cols="145" id="wystext"></textarea><br>
    <button class="wysbutton" onClick="preview()">Preview</button><button class="wysbutton">Post!</button>
</div>
<br><br><br><br><br><br><br><br><br><br><br>
<div class="wyspreview" id="wyspreview">Hit 'Preview' To See the Post General Look<br>Hit 'Post' To Create the Blog Post</div>

And I want to have the Bold button to simply add TEXT HERE. This is the JAvaScript:

function preview() {
    var preview = document.getElementById("wystext").value;
    document.getElementById("wyspreview").innerHTML = preview;
}

function addBold() {
    var text = document.getElementById("wystext").value;
    document.getElementById("wystext").innerHTML = text + "<strong></strong>";
    var text = null;
}

The addBold function works properly, but as soon as I type in the text area, it won't work anymore. Any ideas why ?

Answer 1

Nevermind, found a fix, just edited innerHTML to value.

Might come helpfull for some users.

Answer 2

You should put the text inside the tag:

"<strong>" + text + "</strong>"

It would also be helpful to incude a jsfiddle with an example.