function calcAge(birthDate, birthMonth, birthYear)
{
	if(birthDate=='bad' || birthMonth=='bad'){
		yearsOld = 'bad';
	} else {
		dDate = parseInt(birthDate,10);
		dMonth = parseInt(birthMonth,10);
		dYear = parseInt(birthYear,10);
		
		if (ageForm.monthField.selectedIndex<1) return 'badMonth';
		if (ageForm.dateField.selectedIndex<1) return 'badDate';
		if (isNaN(dYear) || (birthYear.length!=4) || ((dYear + "").length!=birthYear.length)) return 'badYear';
		
		curDate = new Date();
		yearsOld = curDate.getFullYear() - dYear;
		monthsOld = (curDate.getMonth() + 1) - dMonth;
		daysOld = curDate.getDate() - dDate;
		
		if ((monthsOld < 0) || (monthsOld == 0 && daysOld < 0)) yearsOld --;
		if (yearsOld < 0) yearsOld = 'badYear';
	} 
	
	return yearsOld;
}

function theCheck(region)
{
	ageForm = document.forms.theForm;
	birthMonth = ageForm.monthField.options[ageForm.monthField.selectedIndex].value;
	birthDate = ageForm.dateField.value;
	birthYear = "19" + ageForm.yearField.value;
	
	lda = ageForm.locationField.value;
	dAge = calcAge(birthDate, birthMonth, birthYear);

	if (region=='eng')
	{
		if(dAge=='bad' || dAge=='badYear' || dAge=='badMonth' || dAge=='badDate' || ageForm.locationField.value=='bad')
		{
			if(dAge=='bad' || ageForm.locationField.value=='bad'){
				alert("Aub. alle velden invullen");
			}    
			
			if (dAge == 'badMonth'){
				//ageForm.monthField.focus();
				alert("Voer een geldige maand in");
			}
			
			if (dAge == 'badDate'){
				//ageForm.dayField.focus();
				alert("Voer een geldige dag in");
			}
			
			if (dAge == 'badYear'){
				//ageForm.yearField.focus();
				alert("Voer een geldig jaar in");
				ageForm.yearField.value='';
			} 
		}   
		else 
		{ 
			if (dAge >=lda) {
				document.location.href="index.php?age=18plus";
			} else if (dAge < lda && dAge > 0) {
				//document.location.href="http://www.stiva.nl";
				document.location.href="javascript:alert('Sorry, om www.CasaSilva.nl te bezoeken moet je 18 jaar of ouder zijn.')";
				return;
			}
		}
	}
	
	return false;
}