var isW3C = false;
var isNS = false;
var isIE = false;
function BrowserCheck() {
  if (document.layers) {  // NS 4 DOM
    isNS = true;
  }
  else if (document.all && !document.getElementById) { // IE 4 DOM
    isIE = true;
  }
  else if (document.getElementById) { // W3C standards-compliant DOM
    isW3C = true;
  }
  if (isW3C) {
    isNS = (navigator.appVersion.charAt(0)>=4 && (navigator.appName).indexOf("Netscape") != -1);
    isIE = (navigator.appVersion.charAt(0)>=4 && (navigator.appVersion).indexOf("MSIE") != -1);
  }
}
function tierMenu(index) {
   var divName='menu'+index; //DIV ID
   var imName='img'+index; //IMG ID
   if (isW3C == true) { // W3C standards-compliant DOM
      if (document.getElementById(divName).style.display == 'none')
      {
         document.getElementById(imName).src = '..images/interfaccia/icone/meno.gif';
      }
      else
      {
         document.getElementById(imName).src = '..images/interfaccia/icone/piu.gif';
      }

      if (document.getElementById(divName).style.display == 'none')
      {
         document.getElementById(divName).style.display = 'block';
      }
      else
      {
         document.getElementById(divName).style.display = 'none';
      }
/*
      var continua = true;
      var startMenu = 0;
      while (continua)
      {
        startMenu = ++startMenu;
      	if (startMenu != index)
        {
          divName='menu'+startMenu; //DIV ID
          if (document.getElementById(divName) != null)
          {
             imName='img'+startMenu; //IMG ID
             document.getElementById(divName).style.display = 'none';
             document.getElementById(imName).src = '../images/piu.gif';
          } else {
            continua = false;
          }
        }
      }
*/
   }
}