var ns4 = (document.layers)? true : false;
  var ie4 = (document.all)? true : false;
  var ie5n6 = (document.getElementById)? true : false;
  //-----------------
  // helper functions
  //-----------------
  // reload on resize for netscape
  window.onresize = reloadPage;
  function reloadPage() {
    if(ns4) {
      document.location.href = document.location.href;
    }
  }
  function changeImage(srcName, destName, layer) {
  	if (ns4 && layer!=null) {
		  	eval('document.'+layer+'.document.images["'+srcName+'"].src = '+destName+'.src');
	  }
	  else {
  			document [srcName].src = eval(destName+".src");
  	}
  }
  function showLayer(name) {
  	if (ns4) document.layers[name].visibility = "show";
  	else document.getElementById(name).style.visibility = "visible";
  }

  function hideLayer(name) {
  	if (ns4) document.layers[name].visibility = "hide";
  	else document.getElementById(name).style.visibility = "hidden";
  }
  
  function positionLayer(name,x,y) {
  	if (ns4) {
  	  document.layers[name].left = x;
  	  document.layers[name].top = y;
  	}
  	else {
      document.getElementById(name).style.left = x;
      document.getElementById(name).style.top = y;
    }
  }