Access to button
This angularJS code disables button until checkbox is checked. You have to remember setting Internet privilege for external scripts.
<!DOCTYPE html>
<html>
<script src= "http://ajax.googleapis.com/ajax/libs/angularjs/1.3.14/angular.min.js"></script>
<body>
<div ng-app="" ng-init="mySwitch=false">
<input type="checkbox" ng-model="mySwitch"/>Accept regulations before press button.<br><br>
<button ng-disabled="!mySwitch">Click now</button>
</div>
</body>
</html>