var previousLayerId = 'None';



function toggleLayer( whichLayer )

{

  var elem, vis;

  var count = 0;

  if( document.getElementById ) // this is the way the standards work

    elem = document.getElementById( whichLayer );

  else if( document.all ) // this is the way old msie versions work

      elem = document.all[whichLayer];

  else if( document.layers ) // this is the way nn4 works

    elem = document.layers[whichLayer];

  vis = elem.style;

  vis.background == 'red';

  // if the style.display value is blank we try to figure it out here

  if(vis.display==''&&elem.offsetWidth!=undefined&&elem.offsetHeight!=undefined)

  {

    vis.display = (elem.offsetWidth!=0&&elem.offsetHeight!=0)?'':'none';

    previousLayerId = 'None';

    vis.display = (vis.display==''||vis.display=='block')?'none':'';

  }

  else

  {

    if (previousLayerId != 'None')

    {

    	closePreviousLayer(previousLayerId);

    }

    previousLayerId = whichLayer;

    vis.display = (vis.display==''||vis.display=='block')?'none':'';

  }
 

}



function closePreviousLayer(whichLayer2)

{
}


function hideLayer( whichLayer )
{
  var elem, vis;

  if( document.getElementById ) // this is the way the standards work

    elem = document.getElementById( whichLayer );

  else if( document.all ) // this is the way old msie versions work

    elem = document.all[whichLayer];

  else if( document.layers ) // this is the way nn4 works

    elem = document.layers[whichLayer];

  vis = elem.style;

  vis.display = 'none';
  
}


function showLayer( whichLayer )
{
  var elem, vis;

  if( document.getElementById ) // this is the way the standards work

    elem = document.getElementById( whichLayer );

  else if( document.all ) // this is the way old msie versions work

    elem = document.all[whichLayer];

  else if( document.layers ) // this is the way nn4 works

    elem = document.layers[whichLayer];


  vis = elem.style;

  vis.display = 'block';
}