Angular JS ng-show/ hide based on drop-down list selected value

in the following code I have one drop-down list (serviceSmallId) for type of service. It is populated using model info.

There is a second field check-box which should only be visible when drop-down has a selected value of 'Weekly'. I am trying to use ng-show/ hide of angular.

I tried to search for possible solutions but no luck. Can anyone please guide me what I am doing wrong.

<section id="scrubber-view" class="mainbar" data-ng-controller="scrubber as vm">
    <section class="matter">
        <div class="container">

            <div>
                <button class="btn btn-info" ng-click="vm.goBack()"><i class="fa fa-arrow-left"></i>Back</button>
                <button class="btn btn-info" ng-click="vm.cancel()" ng-disabled="!vm.canSave"><i class="fa fa-undo"></i>Cancel</button>
                <button class="btn btn-info" ng-click="vm.save()" ng-disabled="!vm.canSave"><i class="fa fa-save"></i>Save</button>
                <span ng-show="vm.hasChanges" style="color:orange" class="dissolve-animation ng-hide"><i class="fa fa-asterisk"></i></span>
            </div>

            <div class="row">
                <div class="widget wblue">
                    <div data-cc-widget-header title="{{vm.title}}" subtitle="{{vm.scrubber.scrubberId}}"></div>

                    <form class="form-horizontal">

<div class="form-group">
                            <label for="serviceSmallId" class="col-sm-2">Service</label>
                            <div class="col-sm-4">
                                <select class="form-control" id="serviceSmallId" ng-model="vm.scrubber.serviceSmallId"
                                        ng-options="item.dataLookupId as item.description for item in vm.serviceSmalls | orderBy:['sortOrder','description']">
                                </select>
                            </div>
                        </div>



 <div class="form-group" ng-show="vm.scrubber.serviceSmallId.value=='Weekly'">
                            <input class="form-control" type="checkbox" id="fullyFlanged" value="Bar" />
                        </div>

 </form>
                </div>
            </div>
        </div>
    </section>
</section>

Solution

There probably is a more elegant "angular way" solution,

but I updated you code to work here - http://jsbin.com/tupisoriho/1/edit?html,js,output

Explanation of changes

Provided ng-show a value vm.checker
added ng-change to the select element and gave it a function checkerGo which tested to see if dropdown == 'weekly', if yes change vm.checker

Update

there is a more "angular way" - using expressions!
As per @Omri Aharon fiddle/comment below.