<!DOCTYPE html>
<html>
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.4.8/angular.min.js"></script>
<style>
input.ng-invalid {
background-color: lightgreen;
}
</style>
<body>
<form ng-app="" name="testForm">
Employee name: <input name="aName" ng-model="aText" required>
</form>
</body>
</html>
