Javascript onclick change variable value

Question

I am new to JavaScript and I need some help. I am making a website and I have several images of team members that if clicked (so I'm guessing the onclick event) will change the variable values corresponding to that team member. For instance, if I click on a picture of Bill Gates, in a separate div, I need to have a variable (let's say Name) change value to Bill Gates. Then, if I click on an image of Steve Jobs, the variables containing Bill Gates' data will get overwritten with the data of Steve Jobs. How do I do this?

Answer 1

Assuming mark-up like the following:

<div id="gallery">
    <img class="people" data-subject="Steve Jobs" src="path/to/imageOfSteve.png" />
    <img class="people" data-subject="Bill Gates" src="path/to/imageOfBill.png" />
</div>
<span id="caption"></span>

Then a relatively simple, and plain JavaScript, approach:

function identifySubject(image, targetEl) {
    if (!image) {
        return false;
    }
    else {
        var targetNode = document.getElementById(targetEl) || document.getElementById('caption'),
            person = image.getAttribute('data-subject');
            text = document.createTextNode(person);
        if (targetNode.firstChild.nodeType == 3) {
            targetNode.firstChild.nodeValue = person;
        }
        else {
            targetNode.appendChild(text);
        }
    }
}

var images = document.getElementsByClassName('people');
for (var i=0, len=images.length; i<len; i++) {
    images[i].onclick = function(e){
         identifySubject(this, 'caption');
    };
}

JS Fiddle demo.