AngularJsCascardingDropdownlist.html

<div ng-app="drpdwnApp" ng-controller="drpdwnCtrl">
        Order
        <select ng-model="drpdpwnvalue" ng-change="fillCustomerList(drpdpwnvalue)">
            <option ng-repeat="item in ProductList" value="{{item.OrderID}}">{{item.OrderID}}</option>
        </select>
        Customers
        <select>
            <option ng-repeat="item in CustomerList" value="{{item.CustomerName}}">{{item.CustomerName}}</option>
        </select>
    </div>