function showElement( elementId ) {
   var elem = document.getElementById( elementId );
   if (elem) {
      var style = elem.style;
      style.visibility = 'visible';
   }
}

function hideElement( elementId ) {
   var elem = document.getElementById( elementId );
   if (elem) {
      var style = elem.style;
      style.visibility = 'hidden';
   }
}

function disableElement( elementId ) {
   var elem = document.getElementById( elementId );
   if (elem) {
      var style = elem.style;
      style.display = 'none';
   }
}

function enableElement( elementId, block ) {
   var elem = document.getElementById( elementId );
   if (elem) {
      var style = elem.style;
      if (block) {
         style.display = 'block';
      } else {
         style.display = 'inline';
      }
   }
}

function resetVisibility( elementId ) {
	var elem = document.getElementById( elementId );
   var style = elem.style;

   style.visibility = '';
}

function toggleElement( elementId )
{
	var elem = document.getElementById( elementId );
   var style = elem.style;

   style.visibility = ((style.visibility == '') || (style.visibility == 'show')) ? 'hidden' : 'show';
}

function showElementSlideEffect( elementId )
{
	var elem = document.getElementById( elementId );
   var style = elem.style;

   style.display = 'none';
   Effect.SlideDown(elementId);
   style.visibility = 'visible';

}

function hideElementSlideEffect( elementId )
{
	var elem = document.getElementById( elementId );
   var style = elem.style;

   Effect.SlideUp(elementId);
}

function showElementGrowEffect( elementId )
{
	var elem = document.getElementById( elementId );
   var style = elem.style;

   style.display = 'none';
   style.visibility = 'visible';
   Effect.Grow(elementId);

}

function hideElementShrinkEffect( elementId )
{
	var elem = document.getElementById( elementId );
   var style = elem.style;

   Effect.Shrink(elementId);
}

function showElementAppearEffect( elementId )
{
   var elem = document.getElementById( elementId );
   if (elem) {
      var style = elem.style;

      style.display = 'none';
      Effect.Appear(elementId);
      style.visibility = 'visible';
   }
}

function hideElementFadeEffect( elementId )
{
   var elem = document.getElementById( elementId );
   if (elem) {
      var style = elem.style;

   Effect.Fade(elementId, {duration: 0.2});
   }
}

function showLayer( whichLayer ) {
   showElement( whichLayer );
}

function hideLayer( whichLayer ) {
   hideElement(whichLayer);
}

function toggleLayer( whichLayer ) {
   toggleElement( whichLayer );
}