var d = document;
function comment(id) {
    obj = d.getElementById(id);
    if(obj.style.display == 'block') obj.style.display = 'none';
    else obj.style.display = 'block';
}

<!-- COMBO EFFECT -->
Effect.OpenUp = function(element) {
     element = $(element);
     new Effect.BlindDown(element, arguments[1] || {});
}

Effect.CloseDown = function(element) {
     element = $(element);
     new Effect.BlindUp(element, arguments[1] || {});
}

Effect.Combo = function(element) {
     element = $(element);
     if(element.style.display == 'none') { 
          new Effect.OpenUp(element, arguments[1] || {}); 
     }else { 
          new Effect.CloseDown(element, arguments[1] || {}); 
     }
}
<!-- END COMBO EFFECT -->