function check_form() {
  if ($('piece_file').value == '') {
    alert('Selecteer eerst een bestand.');
    return false;
  } else {
    Element.show('pieces_load');
    return true;
  }
}

var images = new Array();
var total_images = 0;
var current_image = 999;

function set_image(thumbnail, full) {
	images[total_images] = new Array();
	images[total_images][0] = thumbnail;
	images[total_images][1] = full;
	total_images++;
}

function choose_image() {
	id = Math.floor(Math.random() * total_images);
	if (id == current_image) {
		choose_image();
	} else {
		current_image = id;
		thumbnail = images[id][0];
		full = images[id][1];
		elemThumb = document.getElementById('circle');
		elemFull = document.getElementById('image');
		if (elemThumb && elemFull) {
			elemThumb.style.backgroundImage = 'url('+thumbnail+')';
			elemFull.style.backgroundImage = 'url('+full+')';
		}
	}
}

function show_image() {
	elemFull = document.getElementById('image');
	if (elemFull) {
		elemFull.style.display = 'block';
	}
	hideLink = document.getElementById('menu_hide_image');
	if (hideLink) {
		hideLink.style.display = 'block';
	}
	elemMain = document.getElementById('main');
	if (elemMain) {
		elemMain.style.display = 'none';
	}
}

function hide_image() {
	elemFull = document.getElementById('image');
	if (elemFull) {
		elemFull.style.display = 'none';
	}
	hideLink = document.getElementById('menu_hide_image');
	if (hideLink) {
		hideLink.style.display = 'none';
	}
	elemMain = document.getElementById('main');
	if (elemMain) {
		elemMain.style.display = 'block';
	}
}

window.onload = choose_image;

function map_show(id) {
	map_hide();
	document.getElementById('map_' + id).style.display = 'block';
}

function map_hide() {
	document.getElementById('map_drenthe').style.display = 'none';
	document.getElementById('map_flevoland').style.display = 'none';
	document.getElementById('map_friesland').style.display = 'none';
	document.getElementById('map_gelderland').style.display = 'none';
	document.getElementById('map_groningen').style.display = 'none';
	document.getElementById('map_limburg').style.display = 'none';
	document.getElementById('map_noordbrabant').style.display = 'none';
	document.getElementById('map_noordholland').style.display = 'none';
	document.getElementById('map_overijssel').style.display = 'none';
	document.getElementById('map_utrecht').style.display = 'none';
	document.getElementById('map_zeeland').style.display = 'none';
	document.getElementById('map_zuidholland').style.display = 'none';
}

function set_artist_id(id) {
  $('artist_id').value = id;
}