function measurementConvert(sourceValue, sourceUnit, targetUnit) {
	var result = 0;
	switch(sourceUnit) {
		case 'cm':
			switch(targetUnit) {
				case 'inch':
					result = sourceValue / 2.54;
					break
			}
			break
		case 'inch':
			switch(targetUnit) {
				case 'cm':
					result = sourceValue * 2.54;
					break
			}
			break
		case 'kg':
			switch(targetUnit) {
				case 'lb':
					result = sourceValue * 2.54;
					break
			}
			break
		case 'lb':
			switch(targetUnit) {
				case 'kg':
					result = sourceValue / 2.2;
					break
			}
			break
	}

	return result;
}

function updateMeasurement(source, sourceUnit, target, targetUnit) {
  var convertedValue;

  source.value = source.value.replace(',', '.');
  if ((sourceUnit == 'cm') || (sourceUnit == 'kg')) {
    source.value = Math.round(source.value);
  }

  convertedValue = measurementConvert(source.value, sourceUnit, targetUnit).toFixed(2);
  if ((sourceUnit == 'inch') || (sourceUnit == 'lb')) {
    convertedValue = Math.round(convertedValue);
  }
  target.value = convertedValue;
}