var commonEventTypeID_Birthday = 1;
var commonEventTypeID_Christmas = 2;
var commonEventTypeID_Wedding = 3;
var commonEventTypeID_Anniversary = 4;

var yearlyEventOnClick_Standard = new Function("updateEventForm();");
var yearlyEventOnClick_Birthday = new Function("alert('Fødselsdage er altid årlige begivenheder.'); return false;");
var yearlyEventOnClick_Christmas = new Function("alert('Juleaften er altid en årlig begivenhed.'); return false;");
var yearlyEventOnClick_Wedding = new Function("alert('Bryllupper er aldrig en årlig begivenhed.'); return false;");

function validateForm(form) {
	var selectedCommonTypeID = form.commonevent.options[form.commonevent.options.selectedIndex].value

	if (form.name.value == '') {
		alert('Indtast venligst et navn til mærkedagen');
		form.name.focus();
		return false;
	}

	if (form.event_day.options[form.event_day.options.selectedIndex].value == '') {
		alert('Vælg venligst dagen for mærkedagen');
		form.event_day.focus;
		return false;
	}

	if (form.event_month.options[form.event_month.options.selectedIndex].value == '') {
		alert('Vælg venligst måneden for mærkedagen');
		form.event_month.focus;
		return false;
	}

	var selectedYear = "";
	if (form.event_year) {
		selectedYear = form.event_year.options[form.event_year.options.selectedIndex].value;
	}
	if (selectedCommonTypeID == commonEventTypeID_Birthday && selectedYear == "") 
	{
		alert('Vælg venligst fødselarens fødeår.');
		form.event_year.focus;
		return false;
	}
	else if (form.onceayear.checked == false && selectedYear == "")
	{
		alert('Vælg venligst året for mærkedagen (eller sæt hak i "Årlig begivenhed")');
		form.event_year.focus;
		return false;
	}

	return true;
}

function updateEventForm() {
	var form = document.getElementById('eventForm');

	var yearBox = document.getElementById('eventYearBox');
	var yearlyEventBox = document.getElementById('yearlyEventBox');

	var yearlyEvent = form.onceayear;
	var selectedCommonTypeID = form.commonevent.options[form.commonevent.options.selectedIndex].value

	if (selectedCommonTypeID == commonEventTypeID_Birthday) {
		//Birthday
		yearlyEvent.checked =	true;
		yearlyEvent.onclick = yearlyEventOnClick_Birthday;
		showCommontypeExplanation("birthday");

		yearBox.style.display = 'block';
	}
	else if (selectedCommonTypeID == commonEventTypeID_Christmas) {
		//Christmas
		yearlyEvent.checked =	true;
		yearlyEvent.onclick = yearlyEventOnClick_Christmas;
		showCommontypeExplanation("christmas");

		yearBox.style.display = 'none';
	}
	else if (selectedCommonTypeID == commonEventTypeID_Wedding) {
		//Wedding
		yearlyEvent.checked =	false;
		yearlyEvent.onclick = yearlyEventOnClick_Wedding;
		showCommontypeExplanation("wedding");

		yearBox.style.display = 'block';
	}
	else {
		yearlyEvent.onclick = yearlyEventOnClick_Standard;
		showCommontypeExplanation(null);

		if (yearlyEvent.checked) {
			yearBox.style.display = 'none';
		}
		else {
			yearBox.style.display = 'block';
		}
	}
}

function showCommontypeExplanation(explanationName)
{
	var explanation_birthday = document.getElementById('commontypeExplanation_Birthday');
	var explanation_wedding = document.getElementById('commontypeExplanation_Wedding');
	var explanation_christmas = document.getElementById('commontypeExplanation_Christmas');
	var explanation_anniversary = document.getElementById('commontypeExplanation_Anniversary');

	explanation_birthday.style.display = "none";
	explanation_wedding.style.display = "none";
	explanation_christmas.style.display = "none";
	explanation_anniversary.style.display = "none";

	switch (explanationName)
	{
		case "birthday":
			explanation_birthday.style.display = "block";
			break;
		case "wedding":
			explanation_wedding.style.display = "block";
			break;
		case "christmas":
			explanation_christmas.style.display = "block";
			break;
		case "anniversary":
			explanation_anniversary.style.display = "block";
			break;
		default:
			break;
	}
	
}