CODE EXAMPLE FOR JAVASCRIPT

html onrightclick

function doSomething(e) {
    var rightclick;
    if (!e) var e = window.event;
    if (e.which) rightclick = (e.which == 3);
    else if (e.button) rightclick = (e.button == 2);
    alert('Rightclick: ' + rightclick); // true or false
}