diff --git a/README.md b/README.md
index 9c7efbc..0ac99ab 100644
--- a/README.md
+++ b/README.md
@@ -39,6 +39,11 @@ echo "The LED3 user is starting"
     sleep 0.5
     echo "0" >> "$LED3_PATH/brightness"
     sleep 0.5
+    else 
+        echo "invalid parameter."
+        echo "To turn on the LED type: ./blink_LED3.sh on"
+        echo "To turn off the LED type: ./blink_LED3.sh off"
+        echo "To make the LED blink type: ./blink_LED3.sh blink"
  fi
  echo "Done"               
 ```