expand macro expands all nested expands

AJS.toInit(function ($) {
    // preload open image
    // contextPath will be expanded by the cssSubstituionTransformer
    new Image().src = "@contextPath/images/icons/grey_arrow_down.gif";

    function expand(e) {
        var expander = $(this),
            expanderIcon = $(".expand-control-icon", expander),
            expanderContent = $(".expand-content", expander.closest(".expand-container")).first();

        if (e.type == "click" || (e.type == "keyup" && e.keyCode == 13)) {
            if (expanderContent.hasClass("expand-hidden")) {
                // open
                expanderContent.fadeIn("fast");
            } else {
                // close
                expanderContent.fadeOut("fast")
            }
            
            expanderContent.toggleClass("expand-hidden");
            expanderIcon.toggleClass("expanded");
        }
    }
    
    $(".expand-control").click(expand).keyup(expand);
});