var xAjax = new Object();
xAjax.Core = function ()
{
	var xmlHttp=null;
	var isAsynchronous = true;
	var isMozilla = false;
	var _this = this;	
	var AJAX_LOADING="caricamento in corso...";
	var isXml=false;
	var requestData="";
	var oHTMLWaitHolder =null;
	var iWaitHolderHeight="";	
	var _callback=null;
	var method="GET";
//	DICHIARAZIONI PUBBLICHE ---------------------------------------------------	

//	EVENTI	
	this.onRequestComplete=function(){}
	
	//METODI
	
	//Creazione oggetto XMLHTTP
	this.newRequest=function(bKeepForm){
		if (!bKeepForm) requestData="";
		if (window.ActiveXObject){
			xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
			if (xmlHttp ==  null){
	        	xmlHttp = new ActiveXObject ("Msxml2.XMLHTTP");            
	       	}
   		}
		else if (window.XMLHttpRequest){
			xmlHttp = new XMLHttpRequest(); isMozilla = true;
   		}
   		else{
       		alert("xAjax.Core non puo\' essere creato.");
			return false
  		}

		return true;
	};
	

	//Invio Richiesta
	this.submitRequest = function(page,callback,bKeepData){
        if (xmlHttp==null)_this.newRequest(bKeepData);
        _callback=callback;
        if (requestData==""){
            sendGetRequest(page);
        }
        else{
            sendPostRequest(page);
        }    
	   	xmlHttp.onreadystatechange = handleServerResponse;	
	}
	
	// Invia una richiesta di tipo GET.
	function sendGetRequest(page)
	{
	    xmlHttp.open("GET", page , isAsynchronous);
	    if (isXml)
	    {
	        if (isMozilla) xmlHttp.overrideMimeType('text/xml');
	        xmlHttp.setRequestHeader("Content-Type", "text/xml");
	    }
        xmlHttp.send(null);
	}
	
	// Invia una richiesta di tipo POST.
	function sendPostRequest(page)
	{
	    xmlHttp.open("POST", page , isAsynchronous);
        xmlHttp.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
        if (isXml)
        {
            xmlHttp.setRequestHeader("Content-Type", "text/xml");
        }
        
        xmlHttp.send(requestData);
	}
	
	//Distruzione oggetto XMLHTTP
 	this.disposeRequest=function(){
		requestData="";
		xmlHttp=null;
	}
	
	this.loadScript=function(scriptName,scriptSrc){
		var script = document.createElement("script");
		script.type = "text/javascript";
		script.id=scriptName;
		script.src = scriptSrc;
		script.defer=true;
		document.getElementsByTagName("head")[0].appendChild(script);  
		//while (!checkJSExists(scriptName)){}
		
	}
	
	this.disposeScript=function(scriptName){
		document.getElementsByTagName("head")[0].removeChild(scriptName);
	}
	
	this.isScriptLoaded=function(scriptName){
		if (document.getElementById(scriptName).readyState==4 || document.getElementById(scriptName).readyState=="loaded")return true;
		return false;
	}
	//PROPRIETA'
	//Output
	this.getResponse=function(bXml){
		return	(bXml)?xmlHttp.responseXML : xmlHttp.responseText;
	}
	
	//Parametri da inviare
	this.setFormData=function(params,bAddParmas){
		if (bAddParmas)
			requestData+=((requestData.length>0) ? "&" : "") + params;
		else
			requestData=params;
	}

	//Parametri da inviare con accodamento a quelli già esistenti
	this.addParamToForm=function(name,value){
		requestData+=((requestData.length>0)? "&" : "") + name + "=" + escape(value);
	}
	
	//Generazione automatica del FORM da inviare
	this.buildForm=function(formName,bAddParmas){
	    var oPost = document.forms[formName].elements;
		var oOptions=null;
		if(!bAddParmas)requestData="";
		for (i=0;i<oPost.length;i++){
			if (oPost[i].name!=""){
				switch (oPost[i].tagName){
					case "INPUT":
						if  (oPost[i].type!="checkbox"){
							requestData+=((requestData.length>0)?"&":"") + oPost[i].name + "=" + escape(oPost[i].value);
						}else{
							if(oPost[i].checked) requestData+=((requestData.length>0)?"&":"") + oPost[i].name + "=" + escape(oPost[i].value);	
						}
						break;
					case "SELECT":
						temp=((requestData.length>0)?"&":"") + oPost[i].name + "="
						oOptions=oPost[i].options
						for (j=0;j<oOptions.length;j++){
							if (oOptions[j].selected) temp+= oOptions[j].value + ",";
						}
						if (temp.charAt(temp.length-1)==",") requestData+=temp.substring(0,temp.length-1) ;
						break;
				}
			}
		}
		if (requestData.charAt(requestData.length-1)=="&") requestData=requestData.substr(requestData.length-1);
	}

	//Dati da tag SELECT 
	this.addSelectToForm=function(formName,selectName){
		
		var oForm = document.forms[formName].elements;
		var oOptions = document.forms[formName][selectName].options;
		
		temp="";
		for (j=0;j<oOptions.length;j++){
		temp+= oOptions[j].value + ",";
		}
		if (temp.charAt(temp.length-1)==",") temp=temp.substring(0,temp.length-1) ;
		if (temp.length>0) requestData+= ((requestData.length>0)? "&" : "") + selectName + "="+ temp;
		
		
	}
	//CARICAMENTO DEL MESSAGGIO DI ATTESA IN UN TAG HTML DEFINITO
	this.LoadingHolder=function(destination){
		oHTMLWaitHolder=document.getElementById(destination);
		
	}
	
	//PERSONALIZZAZIONE DEL MESSAGGIO DI ATTESA
	this.setWaitMessage=function(message){
		AJAX_LOADING=message;
	}

	function handleServerResponse(){
    if(xmlHttp.readyState == 4){
      if (_callback==null){
	  	_this.onRequestComplete.innerHTML=xmlHttp.responseText;
        _this.onRequestComplete();
      }else if (_callback!=""){
       
		eval(_callback.replace("[response]","xmlHttp.responseText"));
      }
      if(oHTMLWaitHolder!=null)oHTMLWaitHolder.style.height=iWaitHolderHeight;
    }
   }	
}