How to make this tooltip like this with pure javascript

Question

I need to use JS no JQuery plugins to make a simple tooltip like on the image below.

Click on ? image should open this tooltip and click again on the same image to close it. I think that it's simple for someone with good JS knowledge but I can't do it anyway :(

This is something that I have tried I know it's not too much but I am simply stuck.
How to display it like on the image, how to hide it when it's open and how to add that little triangle in the corner?

myfiddle

<img id="info" src="http://www.craiglotter.co.za/wp-content/uploads/2009/12/craig_question_mark_icon1.png"/>
<div id="ttip">bla bla</div>

document.getElementById('info').addEventListener('click', function(){
    // how to check if it's visible so I can close tooltip
    document.getElementById('ttip').style.display="block";    
});

#info{margin-left:100px;margin-top:50px;}
#ttip
{
    width: 280px;
z-index: 15001;
top: 0px;
left: 0px;
display: none;
    border-color: #666;
background-color: #fff;
color: #666;
    position: relative;
border: 1px solid #666;
padding: 15px 9px 5px 9px;
text-align: left;
word-wrap: break-word;
overflow: hidden;
}

Answer 1

Clean up the css and this will basically do it:

<script>
    function doTip(e){
          var elem = e.toElement;
          if(elem.getAttribute('data-tip-on')  === 'false') {

            elem.setAttribute('data-tip-on', 'true');
            var rect = elem.getBoundingClientRect();          
            var tipId = Math.random().toString(36).substring(7);
            elem.setAttribute('data-tip-id', tipId);
            var tip = document.createElement("div");
            tip.setAttribute('id', tipId);
            tip.innerHTML = elem.getAttribute('data-tip');
            tip.style.top = rect.bottom+ 10 + 'px';
            tip.style.left = (rect.left-200) + 'px';
            tip.setAttribute('class','tip-box');
            document.body.appendChild(tip);

          } else {

            elem.setAttribute('data-tip-on', 'false');
            var tip = document.getElementById(elem.getAttribute('data-tip-id'));
            tip.parentNode.removeChild(tip);


          }
    }
    function enableTips(){
        var elems = document.getElementsByClassName('quick-tip');
        for(var i = 0; i < elems.length; i++) { 
            elems[0].addEventListener("click", doTip, false);

        }
    }
    window.onload = function(){
        enableTips();
    }
</script>
<style>
    .quick-tip {
        background: black;
        color: #fff;
        padding: 5px;
        cursor: pointer;
        height: 15px;
        width: 15px;
        text-align: center;
        font-weight: 900;
        margin-left: 350px;

    }
    .tip-box {
    /* change dimensions to be whatever the background image is */
        height: 50px;
        width: 200px;
        background: grey;
        border: 1px solid black; 
        position: absolute;
    }
</style>


<div class="quick-tip" data-tip="THIS IS THE TIP! change elements 'data-tip' to change." data-tip-on="false">?</div>

<script>enableTips(); //might be required for jsfiddle, especially with reloads.</script>

Edit: fixed formatting and a bug. jsfiddle: http://jsfiddle.net/u93a3/