Condition wise "Select List" Value Required by JavaScript

 

My Condition is that when "Transport Mode" is "Rental", then "Vendor" Value is required.

Step:1
=====
select P22078_TRANSPORT_MODE
Create Dynamic Action
True Action: Execute JavaScript Code
Code:

if ($v("P22078_TRANSPORT_MODE")=="Rental") {

  var item = $("#P22078_VENDOR_ID");

  item.prop("required",true);

  item.closest(".t-Form-fieldContainer").addClass("is-required");

} else {

  var item = $("#P22078_VENDOR_ID");

  item.prop("required",false);

  item.closest(".t-Form-fieldContainer").removeClass("is-required");

}