You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: My name is Barbara Green. I would like to travel from HOU to HOU, could you help me out?

ASSISTANT: Sure, please share your travel dates.

USER: I would like to change my travel dates, could you help me out?

ASSISTANT: Sorry, no reservation found for the given name.

USER: That's ok. Thank you.

ASSISTANT: Thank you for reaching us.