function Screen(dom) {
	var root = document.getElementById('screen');

	return {
		appendText: appendText,
		clear: clear,
		frame: frame,
		markAsRead: markAsRead,
		menu: menu,
		select: select,
		show: show,
		text: text
	};

	function appendText(message) {
		getTextZone().children[0].textContent += message;
	}

	function clear(elem) {
		if(elem != undefined) {
			root.removeChild(elem);
		} else {
			dom.clear(root);
		}
	}

	function frame(n) {
		root.className = "frame" + n;
	}

	function getTextZone() {
		var textZone = root.getElementsByClassName('text')[0];
		if(textZone == undefined) {
			textZone = dom.make('div', {class: ['text', 'framed']}, [
				dom.make('p')
			]);
			root.appendChild(textZone);
		}
		return textZone
	}

	function markAsRead() {
		getTextZone().classList.add('read');
	}

	function menu(entries) {
		var domEntries = [];
		for(var i = 0; i < entries.length; i++) {
			domEntries.push(dom.make('li', {
				class: i == 0 ? 'selected' : [],
				textContent: entries[i].label
			}, []));
		}
		var ul = dom.make('ul', {class: ['menu', 'framed']}, domEntries);
		root.appendChild(ul);
		return ul;
	}

	function select(cursor) {
		var ul = root.getElementsByClassName('menu')[0];
		ul.getElementsByClassName('selected')[0].className = '';
		ul.children[cursor].className = 'selected';
	}

	function show(elem) {
		root.appendChild(elem);
	}

	function text(message) {
		getTextZone().children[0].textContent = message;
		if(message.length > 0) {
			markAsRead();
		}
	}
}