function $(id){
    return document.getElementById(id);
}

function remove(el){
	if(el && el.parentNode){
		el.parentNode.removeChild(el);
	}
}

function getButton(text){
	var o = '<div class="button"><div class="left"></div><div class="right"></div><div class="center">'+text+'</div></div>';
	return o;
}

var baToMe = '<div onclick="menuPage();">'+getButton('BACK TO MENU')+'</div>';
var startPage = '<h1>iSudoku</h1><ul><li onclick="difficultyPage();">'+getButton('START')+'</li><li onclick="accountPage();">'+getButton('ACCOUNT')+'</li><li onclick="aboutPage();">'+getButton('ABOUT')+'</li><li onclick="location.href=\'../\';">'+getButton('MORE GAMES')+'</li><li onclick="contactPage();">'+getButton('REPORT BUG')+'</li></ul>';

function insertPage(cont, html){
	var p = $('page');
	p.innerHTML = html;
	p.setAttribute('cont', cont);
}

function difficultyPage(){
	var d = '<h1>Difficulty</h1><ul><li onclick="Su.startSudoku(1);">'+getButton('EASY')+'</li><li onclick="Su.startSudoku(2);">'+getButton('MEDIUM')+'</li><li onclick="Su.startSudoku(3);">'+getButton('HARD')+'</li></ul>';
	insertPage('difficulty', d);
}


function menuPage(){
	insertPage('menu', startPage);
}

function accountPage(){
	insertPage('account', '<p>Loading...</p>'+baToMe);
	var aj = new Ajax('texts/account.txt');
	aj.onComplete = function(r){
		insertPage('account', r+baToMe);
	}
}

function loginMe(el){
	var aj = new Ajax('ajax.php', {data:'action=login&un='+el.username.value+'&ps='+el.password.value});
	aj.onComplete = function(r){
		if(r=='false'){
			alert('This user does not exist!');
		}else{
			alert('Now, you are logged in!');
			loggedIn = 1;
			menuPage();
		}
	}
}

function aboutPage(){
	insertPage('about', '<p>Loading...</p>'+baToMe);
	var aj = new Ajax('texts/about.txt');
	aj.onComplete = function(r){
		insertPage('about', r+baToMe);
	}
}

function submitToEmail(el){
	if(el.email.value != '' || el.text.value!=''){
		var aj = new Ajax('ajax.php', {data:'action=send&email='+el.email.value+'&text='+el.text.value});
		aj.onComplete = function(r){
			insertPage('sended', '<p>Your text was sent!</p>'+baToMe);
		}
	}else{
		alert('You must insert required data!');
	}
}


function contactPage(){
	insertPage('contact', '<p>Loading...</p>'+baToMe);
	var aj = new Ajax('texts/contact.txt');
	aj.onComplete = function(r){
		insertPage('contact', r+baToMe);
	}
}

window.onload = function(){
	menuPage();
}