function doControle() {
	var d = document.forms['gastenboek'];
	var a = 0;
	var errorString='';
	if( d.naam.value == '') {
		errorString = 'Je hebt geen naam ingevuld.';
		a=1;
	} else if( d.captcha.value == '') {
		errorString = 'Je hebt de code nog niet ingevuld.';
		a=1;
	}

	if(a > 0) {
			alert(errorString);
			return false;
	} else {
			return true;
	}
}

function getReden( waarde ) {
	var reden= Array();
	var tdz = document.getElementById('select_reden');

	var voorkeursdatum = document.getElementById('reden_afspraak');
	var reden_bellen = document.getElementById('reden_bellen');
	var reden_bellen_2 = document.getElementById('reden_bellen_2');

	if(navigator.userAgent.indexOf("Firefox") != -1) {
		if(tdz.value == 1) {
			voorkeursdatum.style.visibility = "visible";
			voorkeursdatum.style.display = "table-row";
			reden_bellen.style.visibility = "hidden";
			reden_bellen.style.display = "none";
			reden_bellen_2.style.visibility = "hidden";
			reden_bellen_2.style.display = "none";
		} else if(tdz.value == 3) {
			reden_bellen.style.visibility = "visible";
			reden_bellen.style.display = "table-row";
			reden_bellen_2.style.visibility = "visible";
			reden_bellen_2.style.display = "table-row";
			voorkeursdatum.style.visibility = "hidden";
			voorkeursdatum.style.display = "none";
		} else {
			reden_bellen.style.visibility = "hidden";
			reden_bellen.style.display = "none";
			reden_bellen_2.style.visibility = "hidden";
			reden_bellen_2.style.display = "none";
			voorkeursdatum.style.visibility = "hidden";
			voorkeursdatum.style.display = "none";
		}
	} else {
		if(tdz.value == 1) {
			voorkeursdatum.style.visibility = "visible";
			voorkeursdatum.style.display = "inline";
			reden_bellen.style.visibility = "hidden";
			reden_bellen.style.display = "none";
			reden_bellen_2.style.visibility = "hidden";
			reden_bellen_2.style.display = "none";
		} else if(tdz.value == 3) {
			reden_bellen.style.visibility = "visible";
			reden_bellen.style.display = "inline";
			reden_bellen_2.style.visibility = "visible";
			reden_bellen_2.style.display = "inline";
			voorkeursdatum.style.visibility = "hidden";
			voorkeursdatum.style.display = "none";
		} else {
			reden_bellen.style.visibility = "hidden";
			reden_bellen.style.display = "none";
			reden_bellen_2.style.visibility = "hidden";
			reden_bellen_2.style.display = "none";
			voorkeursdatum.style.visibility = "hidden";
			voorkeursdatum.style.display = "none";
		}
	}
}