Add rules using jquery

Question

I have one dropdown menu named as dlUserRole. Inside of it, there are 2 values with index 0 and 1.

I am trying to apply rules for the field ddlSupervisor, like a validation such that if selected index of ddlUserRole is 0 there should be no selection or rule in ddlSupervisor, otherwise there should be at-least 1 selection in ddlSupervisor.

I have a working code for 2 values in ddluserRole dropdown. Now, I added 3rd filed there and I want to apply the same rule, but on selection of 3rd field from ddluserRole (and though I made a choice in ddlSupervisor), I am getting error as

"Please select value between 0 and 1 "

... My half working jQuery code as follows:

$('#ddlUserRole').change(function () {
    var selectedValue = document.getElementById('ddlUserRole');
    if (selectedValue.selectedIndex == '1') {
        $("#ddlSupervisor").rules('add', {
            range: [1, @double.MaxValue],
            messages: {
                range: "Please Enter Supervisor"
            }
        });
    }
    else {
        $("#ddlSupervisor").rules('add', {
            range: [0, @double.MaxValue],
        });
    }
});

I changed the condition to

if (selectedValue.selectedIndex == '1' || selectedValue.selectedIndex == '2')

... but not worked yet. How should I make the above validation?