var http_request = false;

function postFeedback(url, parameters)
{
	http_request = false;
	if(window.XMLHttpRequest)
	{
		http_request = new XMLHttpRequest();
		if(http_request.overrideMimeType)
		{
			http_request.overrideMimeType('text/html');
		}
	}
	else if(window.ActiveXObject)
	{
		try
		{
			http_request = new ActiveXObject("Msxml2.XMLHTTP");
		} 
		catch (e)
		{
			try
			{
				http_request = new ActiveXObject("Microsoft.XMLHTTP");
			}
			catch (e) {}
		}
	}
	if(!http_request)
	{
		alert('Cannot create XMLHTTP instance');
		return false;
	}

	http_request.onreadystatechange = processFeedback;
	http_request.open('POST', url, true);
	http_request.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
	http_request.setRequestHeader("Content-length", parameters.length);
	http_request.setRequestHeader("Connection", "close");
	http_request.send(parameters);
}

function processFeedback()
{
	if(http_request.readyState == 4)
	{
		if(http_request.status == 200)
		{
			var feedback_results = eval('('+http_request.responseText+')');
			if(feedback_results['fstatus'] == 'OK')
			{
				document.getElementById('thanks').style.display = 'block';
				document.getElementById('feedback').style.display = 'none';
				document.getElementById('loading').style.display = 'none';
			}
			else if(feedback_results['fstatus'] == 'CAPTCHA')
			{
				document.getElementById('loading').style.display = 'none';
				alert('Wpisz poprawnie cztery znaki, widoczne na obrazku!');
			}
		}
		else
		{
			alert('There was a problem with the request.');
		}
	}
}

function getChecked(form,name)
{
	var radioObj = document.forms[form].elements[name];
	if(!radioObj)
		return "";
	var radioLength = radioObj.length;
	if(radioLength == undefined)
		if(radioObj.checked)
			return radioObj.value;
		else
			return "";
	for(var i = 0; i < radioLength; i++) {
		if(radioObj[i].checked) {
			return radioObj[i].value;
		}
	}
	return "";
}

function sendFeedback()
{
	var q1 		= getChecked('feedback','q1');
	var q2 		= getChecked('feedback','q2');
	var q3 		= getChecked('feedback','q3');
	var comment	= document.getElementById('comments').value;
	var tid		= document.getElementById('tutorial_id').value;
	var r		= document.getElementById('r').value;
	var cap		= document.getElementById('captcha').value;
	
	document.getElementById('loading').style.display = 'block';
	var par = "q1="+encodeURI(q1)+"&q2="+encodeURI(q2)+"&q3="+encodeURI(q3)+"&comments="+encodeURI(comment)+"&tutorial_id="+encodeURI(tid)+"&r="+encodeURI(r)+"&captcha="+encodeURI(cap);
	postFeedback('/feedback/index.php', par);
}