function openDrawer(drawer) {
   closeDrawer(currentDrawer);
   document.getElementById(drawer + 's')
      .style.display = 'block';
   document.getElementById(drawer)
      .style.backgroundImage = 'url(/img/panel/title-bg-open.jpg)';
   document.getElementById(drawer + '-a')
      .style.backgroundImage = 'url(/img/panel/title-arrow-down.gif)';
   currentDrawer = drawer;
}

function closeDrawer(drawer) {
   document.getElementById(drawer + 's')
      .style.display = 'none';
   document.getElementById(drawer)
      .style.backgroundImage = 'url(/img/panel/title-bg.jpg)';
   document.getElementById(drawer + '-a')
      .style.backgroundImage = 'url(/img/panel/title-arrow.gif)';
}