var keys1 = new Array('w', 'h', 'n', 'wh');
var keys2 = new Array('sum', 'days', 'mw', 'mc');

window.onload = function() {
	for (var i = 0; i < keys1.length; i++) {
		for (var j = 1; j < 5; j++) {
			var obj = document.getElementById(keys1[i] + j);
			obj.onkeyup = function() { Calc(this); }
			obj.onblur  = function() { Calc(this); }
		}
	}
	for (var i = 0; i < keys2.length; i++) {
		var obj = document.getElementById(keys2[i]);
		obj.onkeyup = function() { Calc(this); }
		obj.onblur  = function() { Calc(this); }
	}
	var dummyObj = document.getElementById('w1');
	document.getElementById('battery').onchange = function() { Calc(dummyObj); }
	document.getElementById('days').onkeyup = function() { Calc(dummyObj) }
	document.getElementById('days').onblur  = function() { Calc(dummyObj) }
}

function Calc(obj) {
	if (obj.id != 'battery') {
		obj.value = obj.value.replace(/[^\d]/g, '');
	}
	var total = 0;
	var volt  = document.getElementById('battery').options[document.getElementById('battery').selectedIndex].value;
	var days  = document.getElementById('days').value;
	for (var i = 1; i < 5; i++) {
		var sum = document.getElementById(keys1[0] + i).value;
		for (var j = 1; j < 3; j++) sum = sum * document.getElementById(keys1[j] + i).value;
		total = total + sum;
		document.getElementById(keys1[3] + i).value = sum;
		document.getElementById('sum').value = total;
	}
	if (total > 0) {
		//document.getElementById('mw').value = Math.ceil(total / days * (volt / 10));
		//document.getElementById('mc').value = Math.ceil(total / volt / 0.5 * (volt / 10) * days);
		
		document.getElementById('mw').value = Math.ceil(total * 1.2 / 3);
		document.getElementById('mc').value = Math.ceil((total * 1.2) / (volt * 0.4) * days);
	}
}