function toggleLayer( LayerToDisplay, LayerToHide, TabSelect, TabNotSelect )
{

  // ---------------------------------------------------------
  // Capturer les layer à afficher et à ne pas afficher
  // ---------------------------------------------------------
  var elemDisplay, elemHide, vis,navTabSel,navTabNotSel, ColorTab1, ColorTab2;
  
  if( document.getElementById ) // this is the way the standards work
    {
    elemDisplay = document.getElementById( LayerToDisplay );
    elemHide = document.getElementById( LayerToHide );
    navTabSel = document.getElementById(TabSelect);
    navTabNotSel = document.getElementById(TabNotSelect);

    }	
  else if( document.all ) // this is the way old msie versions work
    {
    elemDisplay = document.all[LayerToDisplay];
    elemHide = document.all[LayerToHide];
    navTabSel = document.all[TabSelect];
    navTabNotSel = document.all[TabNotSelect];

    }
  else if( document.layers ) // this is the way nn4 works
    {
    elemDisplay = document.layers[LayerToDisplay];
    elemHide = document.layers[LayerToHide];
    navTabSel = document.layers[TabSelect];
    navTabNotSel = document.layers[TabNotSelect];
    }

  // ---------------------------------------------------------
  // Rendre visible le layer à afficher	
  // ---------------------------------------------------------
   vis = elemDisplay.style;
   vis.display = 'block';
	
  // ---------------------------------------------------------
  // Rendre invisible le layer à cacher
  // ---------------------------------------------------------
  vis = elemHide.style;
  vis.display = 'none';

  // ---------------------------------------------------------
  // Modifier la couleur des tabs	
  // ---------------------------------------------------------
   ColorTab1 = navTabSel.style; 
   ColorTab2 = navTabNotSel.style;
   
   if(ColorTab1 == 'TrailDetailTab2')
   {
     ColorTab1.background = '#e8e8e8';
     ColorTab2.background = '#e2d99b';
   }
   else
   {
     ColorTab1.background = '#e2d99b';
     ColorTab2.background = '#e8e8e8';
   }

}