function CalculateCost() {
	var frm = document.forms[0], total = 0, Period = 0;

	switch(parseInt(frm.Period.value)) {
		case 3:
			Period = 0;
			break;
		case 6:
			Period = 3;
			break;
		case 12:
			Period = 9;
			break;
	}
	if (frm.Surveys.value > 1) {
		for (var i = 0; i < frm.Surveys.value; i++) {
			if (frm.respondents[i].selectedIndex > 0)
				total += 1200 + Period*50 + (frm.respondents[i].selectedIndex - 1) * 600;
		}
	} else {
		if (frm.respondents.selectedIndex > 0)
			total += 1200 + Period*50 + (frm.respondents.selectedIndex - 1)*600;
	}
	
	frm.total.value = "USD $ "+ total +".00";
};

function isEmpty(s) {
	return ((s == null) || (s.length == 0) || (/^\s+$/.test(s)));
};

function isEmail(s) {
	return s.match(/^.+\@(\[?)[a-zA-Z0-9\-\.]+\.([a-zA-Z]{2,3}|[0-9]{1,3})(\]?)$/);
};

function isAlphaNumeric(s) {
	return !s.match(/[^a-z-A-Z-0-9]/);
};