hideSelectElems=true;

// Calculates the absolute page x coordinate of any element
function pageX(element)
{
  var x = 0;
  do 
  {
    if (element.style.position == 'absolute') 
    {
      return x + element.offsetLeft; 
    }
    else
    {
      x += element.offsetLeft;
      if (element.offsetParent) 
        if (element.offsetParent.tagName == 'TABLE') 
          if (parseInt(element.offsetParent.border) > 0)
          {
            x += 1; 
          }
    }
  }
  while ((element = element.offsetParent));
  return x; 
}

// Calculates the absolute page y coordinate of any element
function pageY(element)
{
  var y = 0;
  do 
  {
    if (element.style.position == 'absolute') 
    {
      return y + element.offsetTop; 
    }
    else
    {
      y += element.offsetTop;
      if (element.offsetParent) 
        if (element.offsetParent.tagName == 'TABLE') 
          if (parseInt(element.offsetParent.border) > 0)
          {
            y += 1; 
          }
    }
  }
  while ((element = element.offsetParent));
  return y; 
}


// Hides HTML select elements that are overlapping the given menu group 
function hideSelectElements(group)
{
  if (document.getElementsByTagName) 
  {
    var arrElements = document.getElementsByTagName('select'); 
    if (hideSelectElems) {
      var groupElement = document.getElementById(group);
      if (groupElement.style.visibility!='hidden'){
	      for (var i = 0; i < arrElements.length; i++) {
			if (objectsOverlapping(groupElement, arrElements[i])){
			  arrElements[i].style.visibility = 'hidden'; 
			}
	      }
      }
    }
  }
}

// Whether the given objects are overlapping 
function objectsOverlapping(obj1, obj2)
{
  var result = true; 
  var obj1Left = pageX(obj1); 
  var obj1Top = pageY(obj1); 
  var obj1Right = obj1Left + obj1.offsetWidth; 
  var obj1Bottom = obj1Top + obj1.offsetHeight;
  var obj2Left = pageX(obj2); 
  var obj2Top = pageY(obj2); 
  var obj2Right = obj2Left + obj2.offsetWidth; 
  var obj2Bottom = obj2Top + obj2.offsetHeight;
  if (obj1Right <= obj2Left || obj1Bottom <= obj2Top || 
      obj1Left >= obj2Right || obj1Top >= obj2Bottom) 
    result = false; 
  return result; 
}

// Restores all HTML select elements on the page 
function restoreSelectElements()
{
  if (document.getElementsByTagName) 
  {
    var arrElements = document.getElementsByTagName('select'); 
    if (hideSelectElems) 
      for (var i = 0; i < arrElements.length; i++) 
        arrElements[i].style.visibility = 'visible'; 
  }
}