var operators = new Array("+");
//var operators = new Array("+", "-", "*");

function AfterLoad()
{
	//window.resizeTo(800,600);
	SkipToNext();
}

function Flashcard_Setup()
{
	var maxInt = GetMaxInteger(GetLevel());
	var operator = document.getElementById("operator");
	var fc1 = document.getElementById("flashcard1");
	var fc2 = document.getElementById("flashcard2");
	var err = document.getElementById("error");
	
	fc1.value = GetRandomInteger(maxInt);
	fc2.value = GetRandomInteger(maxInt);
	fc1.innerHTML = fc1.value;
	fc2.innerHTML = fc2.value;
	operator.value = GetOperator();
	operator.innerHTML = operator.value;

	ResetAnswer();
}

function GetRandomInteger( iMax )
{
	return Math.floor((Math.random() * (iMax+1)));
}

function GetLevel()
{
	return 1;
}

function GetMaxInteger( iLevel )
{
	return iLevel * 10;
}

function GetOperator()
{
	return operators[GetRandomInteger(operators.length-1)];
}

function SubmitAnswer( iAnswer )
{
	var ans = parseInt(iAnswer);
	var val1 = document.getElementById("flashcard1").value;
	var op = document.getElementById("operator").value
	var val2 = document.getElementById("flashcard2").value;
	var evalStr = val1 + " " + op + " " +  val2;
	var correct = eval("ans == (" + evalStr + ")");
	if( correct )
	{
		ShowCorrectMsg(evalStr + " = " + ans);
		Flashcard_Setup();
	}
	else
	{
		ShowErrorMsg();
		document.getElementById("answer").focus();
	}
}

function ResetError()
{
	var err = document.getElementById("error");
	err.style.display = 'none';
	err.innerHTML = '';
	err.className = '';
}

function ResetAnswer()
{
	var answer = document.getElementById("answer");
	answer.value = '';
	answer.focus();
}

function ShowMsg( iMsg )
{
	var err = document.getElementById("error");
	err.style.display = 'block';
	err.innerHTML = iMsg;
}

function ShowCorrectMsg( iExtraMsg )
{
	var msg = 'Correct!!!';
	if( iExtraMsg && typeof(iExtraMsg) == 'string' && iExtraMsg.length > 0 )
		msg += '  ' + iExtraMsg;
	ShowMsg(msg);
	document.getElementById("error").className = 'correct';
}

function ShowErrorMsg( iExtraMsg )
{
	var msg = 'Great try!  Give it another shot!';
	ShowMsg(msg);
	document.getElementById("error").className = 'incorrect';
}

function SkipToNext()
{
	ResetError();
	Flashcard_Setup();
}