// Valida el formulario de preguntas
var	$ = window.$ = function( id ) { return document.getElementById(id); };
var answers = new Array('B','A','A','B','C','B','C','A','B');

function checkQuestions()
{
	if(!allQuestionsAnswered())
	{
		alert('Por favor, marca una opción para cada principio.');
		return;
	}
	var i, answerValue, image, numQuestions = answers.length;
	var numOk = 0;
	for(i=1;i<numQuestions+1; i++) {
		answerValue = getQuestionAnswer(i);
		if(answerValue == -1) continue;

		imageAssessment = $('assessment'+i);
		if(answerValue == answers[i-1])
		{
			imageAssessment.src = 'images/tick.gif';
			numOk++;
		}
		else
			imageAssessment.src = 'images/cruz.gif';
	}
	$('btnResultado').className = 'hide';
	$('btnReset').className = 'show';
	if(numOk <= 3)
		$('resultado1').className = 'show';
	else if(numOk >= 4 && numOk <= 6)
		$('resultado2').className = 'show';
	else if(numOk >= 7 && numOk <= 8)
		$('resultado3').className = 'show';
	else if(numOk == 9)
		$('resultado4').className = 'show';
}
function getQuestionAnswer(questionNumber)
{
	var div, radios;
	div = $('question'+questionNumber);
	radios = div.getElementsByTagName('input');
	return getSelectedRadioButtonValue(radios);
}
function allQuestionsAnswered()
{
	var i, numQuestions = answers.length;
	for(i=1; i<numQuestions+1; i++) {
		if(getQuestionAnswer(i) == -1)
			return false;
	}
	return true;
}
function getSelectedRadioButtonValue(radioObj)
{
	if(!radioObj)
		return false;
	var radioLength = radioObj.length;
	if(radioLength == undefined)
		if(radioObj.checked)
			return radioObj.value;
		else
			return -1;
	for(var i=0; i<radioLength; i++) {
		if(radioObj[i].checked) {
			return radioObj[i].value;
		}
	}
	return -1;
}
function resetRadioButtonOptions(radioObj)
{
	if(!radioObj)
		return false;
	var radioLength = radioObj.length;
	if(radioLength == undefined)
	{
		radioObj.checked = false;
		return 0;
	}
	for(var i=0; i<radioLength; i++) {
		radioObj[i].checked = false;
	}
	return 0;
}
function resetForm()
{
	var i, div, radios, imageAssessment, numQuestions = answers.length;
	for(i=1; i<numQuestions+1; i++) {
		div = $('question'+i);
		radios = div.getElementsByTagName('input');
		resetRadioButtonOptions(radios);
		imageAssessment = $('assessment'+i).src = 'images/pregunta.gif';
	}

	$('resultado1').className = 'hide';
	$('resultado2').className = 'hide';
	$('resultado3').className = 'hide';
	$('resultado4').className = 'hide';
	$('btnReset').className = 'hide';
	$('btnResultado').className = 'show';

	return true;
}