title: I want one input field's value to be equal to another input field at all times
body: <p>I have a checkbox for setting a billing address to the mailing address, so if the checkbox is checked, the two values will always be the same, even if one changes. As of now, I can get the billing address to copy the mailing address once the box is checked, but if you change the values afterwards, the view is not updated. Here is what I have so far: </p>
  
  <p><strong>createcustomer.html:</strong></p>
  
  <pre><code>&lt;section class="mainbar" data-ng-controller="createcustomer as vm"&gt;
  &lt;div class="col-md-4"&gt;
                              &lt;label for="txtMailingAddress1"&gt;Address 1:&lt;/label&gt;
                          &lt;/div&gt;
                          &lt;div class="col-md-8"&gt;
                              &lt;input type="text" id="txtMailingAddress1" name="txtMailingAddress1" value="" data-ng-model="vm.MailingAddress1" class="form-control FloatLeft" required /&gt;
                          &lt;/div&gt;
  
  &lt;input type="checkbox" id="checkboxSameAddress" data-ng-model="vm.IsBillingMailing" data-ng-change="vm.copyMailingAddress()" /&gt;Check if billing address same as mailing address
  
  &lt;div class="form-group"&gt;
                          &lt;div class="col-md-4"&gt;
                              &lt;label for="txtBillingAddress1"&gt;Address 1:&lt;/label&gt;
                          &lt;/div&gt;
                          &lt;div class="col-md-8"&gt;
                              &lt;input type="text" id="txtBillingAddress1" name="txtBillingAddress1" data-ng-model="vm.BillingAddress1" class="form-control FloatLeft" required /&gt;
                          &lt;/div&gt;
                      &lt;/div&gt;
  &lt;/section&gt;
  </code></pre>
  
  <p><strong>createcustomer.js</strong></p>
  
  <pre><code>function copyMailingAddress() {
              if (vm.IsBillingMailing) {
                  vm.BillingAddress1 = vm.MailingAddress1;
              }
              else {
                  vm.BillingAddress1 = '';
              }
          }
  </code></pre>