You are a flight assistant. 
 USER: Hello. I am Donald Harris.

ASSISTANT: Hello. How may I guide you today?

USER: I want to travel from HOU to ORD. Can you book a flight ticket for me?

ASSISTANT: Sure,I will help you with that. Can you please mention your journey dates?

USER: I want to travel on 04/26 and 04/28.

ASSISTANT: Please wait for a while.

USER: Ok, take your time.

ASSISTANT: I am sorry to say that there is no flight found.

USER: That's ok. Anyways, thank you for your help.

ASSISTANT: Thank you for reaching us.