function togglehidden(whichclass) {
    // this is the way the standards work
    var elements = document.getElementsByTagName('tr');
    for(var i=0;i<elements.length;i++) {
        if (elements[i].className == whichclass) {
            if (elements[i].style.display == "") {
                elements[i].style.display = "table-row";
            }
            else {
                elements[i].style.display = "";
            }
        }
    }
}