function checkPoll() {
	var pollForm, questionDivs, errorMsg;

	if (!(pollForm = document.getElementById('PollForm'))) return false;
	if (!(questionDivs = pollForm.getElementsByTagName('div'))) return false;
	errorMsg = "";
	for (i=0; i<questionDivs.length; i++) {
		var questionDiv, answers, answered;
		questionDiv	= questionDivs[i];
		answers = questionDiv.getElementsByTagName('input');
		answered = false;
		if (answers.length > 0 ) {
			if (answers[0].type == 'checkbox') {
				for (teller=0; teller<answers.length; teller++) {
					var answer;
					answer = answers[teller];
					if (answer.checked) answered = true;
				}
			}
			else {
				for (teller=0; teller<answers.length; teller++) {
					if (answers[teller].checked) answered = true;
				}
			}
		}
		if (!answered) errorMsg = "Por favor conteste todas las preguntas.";		
	}
	if (errorMsg.length > 0) {
		alert(errorMsg);
		return false;
	}
	else {
		return true;
	}
}