function TransferHelper() {
	
	this.createDocument = function() {
		if (document.implementation && document.implementation.createDocument) { 
			return document.implementation.createDocument("", "", null); 
		} else if (window.ActiveXObject) { 
			return new ActiveXObject("Microsoft.XMLDOM"); 
		}
		throw "Unsupported Browser";
	};

	this.sendDocument = function(url, doc, callback, method) {
		if(!method) method = "POST";
		me.callback = callback;
		if (window.XMLHttpRequest) { // Mozilla etc. 
			xmlhttp=new XMLHttpRequest(); 
		} else if (window.ActiveXObject) { // IE 
			xmlhttp=new ActiveXObject("Microsoft.XMLHTTP"); 
		}
		if (!xmlhttp) throw "unsupported browser";
		xmlhttp.onreadystatechange=me.updated; 
		xmlhttp.open(method,url,true); 
		xmlhttp.setRequestHeader("Content-Type", "application/x-www-form-urlencoded"); 
		xmlhttp.send(doc); 
	};
	
	this.updated = function() {
		if(xmlhttp.readyState < 4) return;
		try {
			if(xmlhttp.status != 200) return;
		} catch (e) {
			window.status = e;
			return;
		}
		var doc = xmlhttp.responseXML;
		if((!doc || !doc.documentElement) && window.ActiveXObject) {
				doc = new ActiveXObject("Microsoft.XMLDOM");
				doc.async=false;
				doc.loadXML(xmlhttp.responseText);
				if(!doc.firstChild) { //ie try again stripping extended chars.
					var txt = xmlhttp.responseText;
					alert(
						"Error Code: " + doc.parseError.errorCode + "\r\n" + 
						"Reason: " + doc.parseError.reason + "\r\n" + 
						"Line: " + doc.parseError.line + "\r\n" + 
						"Source: " +  doc.parseError.srcText + "\r\n" + 
						"URL: " +  doc.parseError.url + "\r\n"  
					);
					doc.loadXML(cleanText(txt));
				}
		}
		if(!doc || !doc.documentElement) {
			me.callback(null, me);
		} else {
			me.callback(doc, me);
		}
	};
	
	this.lastResponse = function() {
		return xmlhttp.responseText;
	};
	
	this.lastXMLHTTP = null;
	this.callback = null;
	var xmlhttp = null;
	var me = this;
}

function cleanText(str) {
	var ns = "";
	var length = str.length;
	for(var i = 0; i < length; i++) {
		var mychar = str.charCodeAt(i);
		if((mychar < 32 && mychar != 9 && mychar != 10 && mychar != 13) || mychar > 127) continue;
		ns += str.charAt(i); 
	}
	return ns;
};