HTML

<a href="#" id="link">Click me !</a>

JS

var a = document.getElementById('link');

    if (a.addEventListener) {
        a.addEventListener("click", callback, false);
    } else if (a.attachEvent) {
        a.attachEvent("onclick", callback);
    }

    function callback (e) {
        var target = e.target || e.srcElement;

        if (target.innerHTML == 'Hello World!') {
           target.innerHTML = 'Bonjour Monde !';
        } else {
            target.innerHTML = 'Hello World!'; 
        }

        if (e.stopPropagation) {
            e.stopPropagation()  
        }

        if (e.preventDefault) {
            e.preventDefault()  
        }
        return false;
    }