Add the custom messages

resources/views/packages/laracasts/flash/message.blade.php

+@if (Session::has('flash_notification.message'))
+    @if (Session::has('flash_notification.overlay'))
+        @include('flash::modal', ['modalClass' => 'flash-modal', 'title' => 'Notice', 'body' => Session::get('flash_notification.message')])
+    @else
+        <?php $message = Session::get('flash_notification.message'); ?>
+        <?php $level = Session::get('flash_notification.level'); ?>
+        <?php if ($level == 'danger'): ?>
+            <script type="text/javascript">
+                $(document).ready( function() {
+                    alertify.error( "<?php echo $message; ?>" );
+                });
+            </script>
+        <?php endif; ?>
+        <?php if ($level == 'success'): ?>
+            <script type="text/javascript">
+                $(document).ready( function() {
+                    alertify.success( "<?php echo $message; ?>" );
+                });
+            </script>
+        <?php endif; ?>
+    @endif
+@endif

resources/views/packages/laracasts/flash/modal.blade.php

+<div id="flash-overlay-modal" class="modal fade {{ $modalClass or '' }}">
+    <div class="modal-dialog">
+        <div class="modal-content">
+            <div class="modal-header">
+                <button type="button" class="close" data-dismiss="modal" aria-hidden="true">&times;</button>
+
+                <h4 class="modal-title">{{ $title }}</h4>
+            </div>
+
+            <div class="modal-body">
+                <p>{{ $body }}</p>
+            </div>
+
+            <div class="modal-footer">
+                <button type="button" class="btn btn-default" data-dismiss="modal">Close</button>
+            </div>
+        </div>
+    </div>
+</div>