/**
 * toggle_layer.js
 * Used to toggle a layer block and none
 * */
function toggleLayer( whichLayer, whichDisplay )
{
  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 = whichDisplay;
}