var trackEvent = function(params) {

	this.returnData;
	
	var _self = this;

	this.onData = null;

	var url 	= '/flash/xch.php';
	var method 	= 'POST';

	var req = new XHR();
		req.open(method, url, true);
		req.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
		req.send(ued_encode(params));
				
		req.onreadystatechange = function () {
	        if (req.readyState == 4) {
	        	
	        	_self.returnData = JSON.parse(req.responseText);
	        	
	        	if(typeof(_self.onData == Function)){
	        		_self.onData();
	        	}
	        }
	    };
}

//ued_encode() will take an array as its argument and return the data encoded in UED format - as a string.
//http://www.openjs.com/scripts/data/ued_url_encoded_data/
function ued_encode(arr,current_index) {
	var query = ""
	if(typeof current_index=='undefined') current_index = '';

	if(typeof(arr) == 'object') {
		var params = new Array();
		for(key in arr) {
			var data = arr[key];
			var key_value = key;
			if(current_index) {
				key_value = current_index+"["+key+"]"
			}

			if(typeof(data) == 'object') {
				if(data.length) { //List
					for(var i=0;i<data.length; i++) {
						params.push(key_value+"[]="+ued_encode(data[i],key_value)); //:RECURSION:
					}
				} else { //Associative array
					params.push(ued_encode(data,key_value)); //:RECURSION:
				}
			} else { //String or Number
				params.push(key_value+"="+encodeURIComponent(data));
			}
		}
		query = params.join("&");
	} else {
		query = encodeURIComponent(arr);
	}

	return query;
}