Display help on error.

Change-Id: I379a635360c99eb79bc9bb660e4c3b2659003c95

diff --git a/examples/mqtt_clear_retain.py b/examples/mqtt_clear_retain.py
index 13f5754ae1a2e76d8454aee19a4bb6b3f72c134b..dc35f67776c6dc1e4c99d4897832f7532d7a2ea4 100755 (executable)
--- a/examples/mqtt_clear_retain.py
+++ b/examples/mqtt_clear_retain.py
@@ -94,7 +94,8 @@ def main(argv):
             verbose = True
 
     if topic == None:
-        print("You must provide a topic to clear.")
+        print("You must provide a topic to clear.\n")
+        print_usage()
         sys.exit(2)
 
     mqttc = mqtt.Client(client_id)