isMouseover = false;
isDragging = false;
id_layer = '';
id_layer_title = '';

function MouseDownLayer(e)
{
  if (id_layer != '') {
   isIE = document.all;
   documentTag = isIE ? "BODY" : "HTML";
   srcElement = isIE ? event.srcElement : e.target;  
  layerElement = document.getElementById(id_layer);
  
   while ((srcElement.id != id_layer_title) && (srcElement.tagName != documentTag))
   {
      srcElement = isIE ? srcElement.parentElement : srcElement.parentNode;
   }  
   if (srcElement.id == id_layer_title)
   {
      offsetX = isIE ? event.clientX : e.clientX;
      offsetY = isIE ? event.clientY : e.clientY;
      currentX = parseInt(layerElement.style.left);
      currentY = parseInt(layerElement.style.top);
      isDragging = true;
      document.onmousemove = MouseMoveLayer;
  }
  }
}

function MouseMoveLayer(e)
{
   if (!isDragging) return;
  
   if (document.all)
   {
      layerElement.style.left = currentX+event.clientX-offsetX; 
      layerElement.style.top = currentY+event.clientY-offsetY;
   }
   else
   {
      layerElement.style.left = currentX+e.clientX-offsetX+'px'; 
      layerElement.style.top = currentY+e.clientY-offsetY+'px';
   }
   return false;  
}

document.onmousedown = MouseDownLayer;
document.onmouseup = Function("isDragging=false");