public double getBMI( String weightUnit, String HeightUnit, double h, double, w){
  double weight;
  if(weightUnit.equals("pound"){
      weight = w * poundConversion;

  }
  if(heightUnit.equals("foot") && (weightUnit.equals("pound") || weightUnit.equals("kilogram"))) {
    double height = h * footConversion;
    return weight / (height * height);
  }
  else if (heightUnit.equals("inch" && (weightUnit.equals("pound") || weightUnit.equals("kilogram"))){
    double height = h * inchConversion;
    return weight / (height * height);
  }
  return -1;
}