dynamic messages with ngMessages

http://angularjs.org/

HTML

<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.4.3/angular.min.js"></script>
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.4.3/angular-messages.min.js"></script>
<div ng-controller="myCtrl">
    <form name="myForm">
        <label>Email address
            <input type="email" ng-model="data.email" name="myEmail" ng-minlength="5" ng-maxlength="100" required />
        </label>
        <div ng-messages="myForm.myEmail.$error" role="alert">
            <div ng-message-exp="'required'">You did not enter your email address</div>
            <div ng-message-exp="asit">Your email must be between 5 and 100 characters long</div>
        </div>
    </form>
</div>

JavaScript

var app = angular.module('app', ['ngMessages']);

angular.module('app').controller('myCtrl', function ($scope) {
    $scope.email = "";
    $scope.asit = true;
});