var languageKey_Nl = 'nl';
	var languageKey_En = 'en';
	// =========================================================================
	// e: expression, re: regExp
	function regExp_test(e, re) {
		var temp;
		
		temp = re.test(e);
		if (!temp) { temp = re.test(e) }
		
		return temp;
	}
	// -------------------------------------------------------------------------
	regExp_eMail = new RegExp('^[a-z0-9._%+-]{1,}@[a-z0-9.-]+\\.+[a-z]{2,4}', 'i');
	regExp_phone = new RegExp('^\\+?[\\d\\s\\-\\(\\)]*$', '');
	// =========================================================================
	// f: form, l: languageKey
	function checkForm(f, lk) {
		var question, name, phone, mobile, eMail;
		var message;
		
		question = gfev('question', f);
		name = gfev('name', f);
		phone = gfev('phone', f);
		mobile = gfev('mobile', f);
		eMail = gfev('e-mail', f);
		
		var message = '';
		
		switch(lk) {
		case languageKey_Nl:
			if (!question) { message = message + '- uw vraag' }
			
			if (!name) {
				if (message) { message = message + '\n' }
				message = message + '- uw naam'
			}
			
			if (!((!!phone && regExp_test(phone, regExp_phone)) || (!!mobile && regExp_test(mobile, regExp_phone)) || regExp_test(eMail, regExp_eMail))) {
				if (message) { message = message + '\n' }
				message = message + '- een correct vast of mobiel telefoonnummer of een e-mail-adres'
			}
			
			if (message) { message = 'Om uw aanvraag te kunnen verwerken hebben wij ook de volgende gegevens van u nodig:\n' + message }
			
			break;
		case languageKey_En:
			if (!question) { message = message + '- your question' }
			
			if (!name) {
				if (message) { message = message + '\n' }
				message = message + '- your name';
			}
			
			if (!((!!phone && regExp_test(phone, regExp_phone)) || (!!mobile && regExp_test(mobile, regExp_phone)) || regExp_test(eMail, regExp_eMail))) {
				if (message) { message = message + '\n' }
				message = message + '- a correct phone or mobile number or an e-mail address'
			}
			
			if (message) { message = 'To be able to process your request, we also need the following information:\n' + message }
			
			break;
		}
		
		if (message) {
			alert(message);
		} else {
			return true;
		}
	}
	// -------------------------------------------------------------------------
	// f: form, lk: languageKey
	function submitForm(f, lk) {
		if (checkForm(f, lk)) {
			if (f.elements['process']) { f.elements['process'].value = 'true' }
			
			f.submit();
		}
	}