function load_size()
{
// declare variables
var result = 0;
var qty;
var usage;
var rating;
var energy;

//loop through all the rows
for  (var i = 0; i < 6; i ++)
	{
	//fetch values
	qty = document.forms[0].qty[i].value;
	usage = document.forms[0].usage[i].value;
	rating = document.forms[0].rating[i].value;

	//check usage doesn't exceed 24 hours
	if (usage > 24) {
		alert("Günlük Kullanım 24 Saati Geçemez!");
		return false;}

	//calculate result for row
	energy = qty * usage * rating;
	energy = Math.round(energy);

	// verify result is a number
	var verify = isNaN(energy);
	if (verify) {
	alert ("Bütün Girdiler Rakam Olmalıdır");
	return false;
	};

	//check for calculated result
	if (energy != 0)

		//write result to row
		document.forms[0].energy[i].value = energy;

	else
		//fetch manually entered result and multiply by qty
		{energy = document.forms[0].energy[i].value * qty;
		energy = Math.round(energy);
		}

	//add row to total
	result += energy;
	}

//write total
document.forms[0].result.value = result;
}