//Конвертер
function converter($a, $b, $coefficient) {
	$value = eval("document.getElementById('" + $a + "').value.replace(',','.')");
	if (isNaN($value)) $value = '';
	else $value = Math.round($value * $coefficient);
	eval("document.getElementById('" + $b + "').value = " + $value + ";");
}