window.onload = function () {    var navigation = document.getElementById("some_element_high_up_in_the_hierarchy");
    navigation.onclick = function (evt) {
        // Event tweaks, since IE wants to go its own way...
        var event = evt || window.event;
        var target = event.target || event.srcElement;
        if(target.className && target.className==='someClass') {
           //do your stuff here
        }
    }
};