Cancel/clear form when using payment protocol

js/controllers/send.js

@@ -492,6 +492,16 @@ angular.module('copayApp.controllers').controller('SendController',
       }
     };
 
+    $scope.cancelSend = function(form) {
+      delete $rootScope.merchant;
+      $rootScope.merchantError = false;
+      form.address.$setViewValue('');
+      form.address.$render();
+      form.amount.$setViewValue('');
+      form.comment.$setViewValue('');
+      form.$setPristine();
+    };
+
     $scope.onChanged = function() {
       var value = $scope.address || '';
       var uri;

views/send.html

@@ -173,7 +173,12 @@
             </div>
 
             <div class="row">
-              <div class="large-12 columns text-right">
+              <div class="large-6 medium-6 small-6 columns text-left">
+                <a ng-click="cancelSend(sendForm)" class="button warning m0" ng-show="!!$root.merchant">
+                  Cancel
+                </a>
+              </div>
+              <div class="large-6 medium-6 small-6 columns text-right">
                 <button type="submit" class="button primary m0" ng-disabled="sendForm.$invalid || loading">
                   Send
                 </button>