function round( num, signs ) {
	if( !signs ) signs = 0;
	if( signs < 0 ) return num;
	if( signs == 0 ) {
		return Math.round( num );
	}

	with( Math ) {
		num *= pow( 10, signs );
		num = round( num );
		num *= 1 / pow( 10, signs );
	}
	
	return num;
}

function conv( val, _from, _to ) {
	return prepare_out( round( ( _to.value / _from.value ) * prepare_in( val ), 4 ) );
}