var target;

function lastChanged(x){
	target = x;
}
function conv()
{
	var totalbt;
	
	if (document.getElementById(target).id == 'bt') totalbt = eval(document.getElementById(target).value);	
	else if (document.getElementById(target).id == 'kb') totalbt = document.getElementById(target).value * 1024;
	else if (document.getElementById(target).id == 'mb') totalbt = document.getElementById(target).value * 1048576;
	else if (document.getElementById(target).id == 'gb') totalbt = document.getElementById(target).value * 1073741824;
	else if (document.getElementById(target).id == 'tb') totalbt = document.getElementById(target).value * 1099511627800;
	
	if (document.getElementById(target).value == "") totalbt = 0;
	
	document.converter.bt.value = addCommas(totalbt.toFixed(0));
	document.converter.kb.value = addCommas((totalbt / 1024).toFixed(2));
	document.converter.mb.value = addCommas((totalbt / 1048576).toFixed(2));
	document.converter.gb.value = addCommas((totalbt / 1073741824).toFixed(2));
	document.converter.tb.value = addCommas((totalbt / 1099511627800).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;
}