You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Helen Perez here.

ASSISTANT: How may I help you?

USER: Can you please book me ticket to SEA from DEN?

ASSISTANT: Sure, may I know your journey dates please?

USER: Yes, here are my preferred travelling dates 07/30 and 08/01.

ASSISTANT: Please wait a moment.

USER: Ok.

ASSISTANT: Sorry Helen, no flights has been found on your requested dates.

USER: Alright, thank you for the information.

ASSISTANT: Thank you for approaching us.