// funzioni cross-browser
// Copyright 2001-2007 Michael Foster (Cross-Browser.com)

function xDef()
{
  for(var i=0; i<arguments.length; ++i){if(typeof(arguments[i])=='undefined') return false;}
  return true;
}

function xStr(s)
{
  for(var i=0; i<arguments.length; ++i){if(typeof(arguments[i])!='string') return false;}
  return true;
}

function xDisplay(e,s)
{
  if ((e=xGetElementById(e)) && e.style && xDef(e.style.display)) {
    if (xStr(s)) {
      try { e.style.display = s; }
      catch (ex) { e.style.display = ''; } // Will this make IE use a default value
    }                                      // appropriate for the element?
    return e.style.display;
  }
  return null;
}

function xGetElementsByTagName(t,p)
{
  var list = null;
  t = t || '*';
  p = xGetElementById(p) || document;
  if (typeof p.getElementsByTagName != 'undefined') { // DOM1
    list = p.getElementsByTagName(t);
    if (t=='*' && (!list || !list.length)) list = p.all; // IE5 '*' bug
  }
  else { // IE4 object model
    if (t=='*') list = p.all;
    else if (p.all && p.all.tags) list = p.all.tags(t);
  }
  return list || [];
}

function xGetElementById(e)
{
  if(typeof(e)!='string') return e;
  if(document.getElementById) e=document.getElementById(e);
  else if(document.all) e=document.all[e];
  else e=null;
  return e;
}