document.observe("dom:loaded", function() {
    var triggers = $("content").select(".tooltip");
    triggers.each(function(link) {
        tt = link.getAttribute("rel");
        link.observe("mouseover", function(e) {
            displayTooltip(tt, e);
        });
        link.observe("mouseout", function(e) {
            hideTooltip(tt);
        });
    });
});

function displayTooltip(element, event) {
    $(element).setStyle({ "top": Event.pointerY(event) + "px" });
    $(element).setStyle({ "left": Event.pointerX(event) + "px" });
    $(element).show();
}
function hideTooltip(element) {
    $(element).hide();
}