function change_footer(class_id) {
    //alert(class_id)
    if (class_id == -1) {
        parent.frames["footer"].location.href = 'default.asp';    
        }
    else {
        parent.frames["footer"].location.href = 'class_detail.asp?class_id=' + class_id;
        }
   	}
  
  function toggle_attachments() {
    if (document.forms[0].attachment_flag.checked == true) {
        document.forms[0].attachment_link_1.disabled = false;
        document.forms[0].attachment_link_2.disabled = false;
        }
    else {
        document.forms[0].attachment_link_1.disabled = true;
        document.forms[0].attachment_link_2.disabled = true;
        }
    }
    
  function update_page_url(url, class_id) {
    if (class_id == -1) {
        return;
        }
    window.location.href = url + "?class_id=" + class_id;
    }