I am creating an application where I am having Age range, weight range, height range and etc. So in these fields I am using two text boxes for each. For example for Age range I am using Age From and Age To these two textboxes and so on for the other properties. But I am trying to find a solution to compare the Age From and Age To to check whether the Age To is not getting bigger than the Age From and vice versa. To achieve this I have downloaded Foolproof from NUGET and doing like this:

```
    [GreaterThan("WeightFrom",ErrorMessage="Please verify the Weight Range")]
    public string WeightTo { get; set; }

```

But this Validator checks for the field as a required field whether it is not. Because it is possible that user may not fill this criteria at all but if they fill then I need to check the input to ensure that the Weight To is greater than the Weight From value. So, please advise me how do I achieve this.Is there any other way of doing this? Thanks.