function revealElement(id) {
	var element = document.getElementById(id);
	if (element != null) {
		element.style.display = 'block';
	}
}

function setMaxLength(object, maxLen) {
	return (object.value.length <= maxLen);
}

function validateGuestBookForm(number1, number2) {
	var nameField = document.getElementById("meno");
	var textField = document.getElementById("vzkaz");
	var control = document.getElementById("control");
	
	if (control.value != number1 + number2) {
		alert('Zle!');
		return false;
	}
	
	if (nameField.value == "") {
		alert('Všetky polia su povinné!');
		return false;
	}
	if (textField.value == "") {
		alert('Všetky polia su povinné!');
		return false;
	}
	document.guestbook.submit();
	return true;
}

function copyToHidden(c1, c2) {
	var num1 = document.getElementById("c1");
	var num2 = document.getElementById("c2");
	var num3 = document.getElementById("c3");
	var control = document.getElementById("control");
	
	num1.value = c1;
	num2.value = c2;
	num3.value = control.value;
}

function removeAnswerTo() {
	var row = document.getElementById("answerToRow");
	var input = document.getElementById("answerTo");
	
	input.value = "";
	row.style.display = 'none';
}

function setAnswerTo(name) {
	var row = document.getElementById("answerToRow");
	var input = document.getElementById("answerTo");
	
	input.value = name;
	row.style.display = '';
}