var DOM = (document.getElementById) ? true : false;
var IE4 = (document.all) ? true : false;
var NS4 = (document.layers) ? true : false;

function show(itemtoshow)
{
 if (DOM)
  {
 document.getElementById(itemtoshow).style.visibility = 'visible';
  }
 else if (IE4)
  {
   document.all[itemtoshow].style.visibility = 'visible';
  }
 else if (NS4)
  {
 document.layers[itemtoshow].visibility = 'show';
	 }
 else
  {
 
  }
}

function hide(itemtohide)
{
 if (DOM)
  {
 document.getElementById(itemtohide).style.visibility = 'hidden';
  }
 else if (IE4)
  {
   document.all[itemtohide].style.visibility = 'hidden';
  }
 else if (NS4)
  {
 document.layers[itemtohide].visibility = 'hide';
	 }
 else
  {

  }
}