function onquestionnaire() {
	var errors = 0;
	var result = 0;
	var questions = 40;

	if (document.getElementById("registered").checked == false) {
		if (document.getElementById("name").value == "") errors++;
		if (!isValidEmail(document.getElementById("email").value)) errors++;

	} //if...

	for (var i=1; i<questions; i++) {
		var question = "question" + i;

		if (document.getElementById(question).options.selectedIndex != 0) {
			result += parseInt(document.getElementById(question).options[document.getElementById(question).options.selectedIndex].value);

		} else {
			errors++;

		} //else...

	} //for...

	if (errors > 0) {
		alert("Some fields are invalid")

	} else {
		if (result < 200) {
			document.getElementById("redirect").value = "oq_result1.php";

		} else if (result >= 200 && result <=300) {
			document.getElementById("redirect").value = "oq_result2.php";

		} else if (result > 300) {
			document.getElementById("redirect").value = "oq_result3.php";

		} //else if...

		document.getElementById("questionnaire_form").submit();

	} //else...

} //onquestionnaire()