/** Crea un oggetto ajax */
function createAJAX()
{
	if (window.XMLHttpRequest)
		return new XMLHttpRequest();
	else if (window.ActiveXObject)
		return new ActiveXObject("Microsoft.XMLHTTP");
  else
    return null;
}

/** Estende la stringa con la funzione TRIM */
String.prototype.trim = function()
{
  return this.replace(/^\s+|\s+$/g, "");
}

/** URLENCODE per il passaggio dati via GET o POST */
function urlencode(str)
{
   // http://kevin.vanzonneveld.net
   // +   original by: Philip Peterson
   // +   improved by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
   // +      input by: AJ
   // +   improved by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
   // %          note: info on what encoding functions to use from: http://xkr.us/articles/javascript/encode-compare/
   // *     example 1: urlencode('Kevin van Zonneveld!');
   // *     returns 1: 'Kevin+van+Zonneveld%21'
   // *     example 2: urlencode('http://kevin.vanzonneveld.net/');
   // *     returns 2: 'http%3A%2F%2Fkevin.vanzonneveld.net%2F'
   // *     example 3: urlencode('http://www.google.nl/search?q=php.js&ie=utf-8&oe=utf-8&aq=t&rls=com.ubuntu:en-US:unofficial&client=firefox-a');
   // *     returns 3: 'http%3A%2F%2Fwww.google.nl%2Fsearch%3Fq%3Dphp.js%26ie%3Dutf-8%26oe%3Dutf-8%26aq%3Dt%26rls%3Dcom.ubuntu%3Aen-US%3Aunofficial%26client%3Dfirefox-a'

   var histogram = {}, histogram_r = {}, code = 0, tmp_arr = [];
   var ret = str.toString();

   var replacer = function(search, replace, str) {
       var tmp_arr = [];
       tmp_arr = str.split(search);
       return tmp_arr.join(replace);
   };

   // The histogram is identical to the one in urldecode.
   histogram['!']   = '%21';
   histogram['%20'] = '+';

   // Begin with encodeURIComponent, which most resembles PHP's encoding functions
   ret = encodeURIComponent(ret);

   for (search in histogram) {
       replace = histogram[search];
       ret = replacer(search, replace, ret) // Custom replace. No regexing
   }

   // Uppercase for full PHP compatibility
   return ret.replace(/(\%([a-z0-9]{2}))/g, function(full, m1, m2) {
       return "%"+m2.toUpperCase();
   });

   return ret;
}