function calc(form)
{
	var multirate = 0;
	var go;
	
	if (form.length_h.value == "HH" || form.length_h.value == "") form.length_h.value = 0;
	if (form.length_m.value == "MM" || form.length_m.value == "") form.length_m.value = 0;
	if (form.length_s.value == "SS" || form.length_s.value == "") form.length_s.value = 0;
	var total_length = ((form.length_h.value * 3600) + (form.length_m.value * 60) + eval(form.length_s.value));
	
	if (form.format.value == "525NTSC" && form.evt.value == "8bit") multirate = 20;
	else if (form.format.value == "525NTSC" && form.evt.value == "10bit") multirate = 27;
	else if (form.format.value == "625PAL" && form.evt.value == "8bit") multirate = 20;
	else if (form.format.value == "625PAL" && form.evt.value == "10bit") multirate = 26;
	else if (form.format.value == "720p" && form.evt.value == "8bit") multirate = 105;
	else if (form.format.value == "720p" && form.evt.value == "10bit") multirate = 140;
	else if (form.format.value == "1080_24" && form.evt.value == "8bit") multirate = 95;
	else if (form.format.value == "1080_24" && form.evt.value == "10bit") multirate = 127;
	else if (form.format.value == "1080_25" && form.evt.value == "8bit") multirate = 99;
	else if (form.format.value == "1080_25" && form.evt.value == "10bit") multirate = 132;
	else if (form.format.value == "1080_30" && form.evt.value == "8bit") multirate = 119;
	else if (form.format.value == "1080_30" && form.evt.value == "10bit") multirate = 158;
	else multirate = 0;
				
	go = total_length * multirate;
	if (go < 0) go = 0;
	
	form.mbout.value = addCommas(go.toFixed(2));
	form.gbout.value = addCommas((go / 1024).toFixed(2));
}

function addCommas(nStr)
{
	nStr += '';
	x = nStr.split('.');
	x1 = x[0];
	x2 = x.length > 1 ? '.' + x[1] : '';
	var rgx = /(\d+)(\d{3})/;
	while (rgx.test(x1)) {
		x1 = x1.replace(rgx, '$1' + ',' + '$2');
	}
	return x1 + x2;
}