 separate elements for each of the possible errors that <code>myField</code> could have.
The <code>ngMessage</code> attribute is used to declare which element(s) will appear for which error - for example,
setting <code>ng-message=&quot;required&quot;</code> specifies that this particular element should be displayed when there
is no value present for the required field <code>myField</code> (because the key <code>required</code> will be <code>true</code> in the object
<code>myForm.myField.$error</code>).</p>
