var NNE = document.getElementById;
var IE = document.all;
var bolVysledok=false;

var one = '1';
var two = '2';
var three = '3';
var four = '4';
var five = '5';
var six = '6';
var seven = '7';
var eight = '8';
var nine = '9';
var zero = '0';
var plus = '+';
var minus = '-';
var multiply = '*';
var divide = '/';
var decimal = '.';
var pamet = '';
var lzavorka = '(';
var rzavorka = ')';

window.onerror = handleError;

function handleError() {
	return false;
}

function KeyEnter(e,obj) {	
	var keyPressed,keyChar;
	if(document.all) 	//IE		
		keyPressed=e.keyCode
	else				//NN
		keyPressed= e.which;				
		
	switch (keyPressed) {
		case 13 : compute(obj); 		//Stlacene Enter
			break;
		case 67 : obj.expr.value = '';	//Stlacene C
			bolVysledok=false;
			break;
		default:
			keyChar=String.fromCharCode(keyPressed);
			if ((keyPressed>95) && (keyPressed<106)) {
					keyPressed=keyPressed-48;
					keyChar=String.fromCharCode(keyPressed);
			} else if (keyPressed>105) {
				switch (keyPressed) {
					case 111 : keyChar=divide;
						break;					
					case 110 : keyChar=decimal;
						break;
					case 109 : keyChar=minus;
						break;
					case 107 : keyChar=plus;
						break;
					case 106 : keyChar=multiply;
						break;
				}
			}
			
			if (bolVysledok && ((keyChar != plus && keyChar != divide) && (keyChar != minus && keyChar != multiply))) 
						obj.expr.value = keyChar;						
							
			bolVysledok=false;	
			break;	
	}
	return true;
}

function compute(obj) {	
	if (obj.expr.value) {
		obj.expr.value = eval(obj.expr.value.replace(',', '.'));
		bolVysledok=true;
	}	
	getFocus();
}

function enter(obj, string){	
	if (bolVysledok && ((string != plus && string != divide) && (string != minus && string != multiply))) 
		obj.expr.value = string;
	else 
		obj.expr.value += string;			
	
	bolVysledok=false;	
	getFocus();
}

function mem(obj){
	if (obj.expr.value) {
		pamet = '('+obj.expr.value+')';
		document.getElementById('memory').style.color='red';
/*
		if (NNE) {
			document.getElementById('memory').innerHTML='M';
		} else if (IE) {
			memory.innerHTML='M';
		}
*/
	}	
	getFocus();
}

function memCl() {
	pamet = '';
	document.getElementById('memory').style.color='#A1AFB9';
/*
	if (NNE) {
		document.getElementById('memory').innerHTML='';
	} else if (IE) {
		memory.innerHTML='';
	}
*/
	getFocus();
}	

function getFocus() {
    if (NNE) {
		document.getElementsByName('expr')[0].focus();
	} else if (IE) {
		document.all['expr'].focus();
	}	
}