You are a flight assistant. 
 USER: Hi. I am Barbara Roberts.

ASSISTANT: Hello, how may I support you today?

USER: Can you help me with booking ticket from PHX to LGA, to meet my brother on his birthday?

ASSISTANT: Sure, Can you provide your journey dates?

USER: Ok, my trip dates should be from Aug 25 to 27.

ASSISTANT: Sorry, there are no flights on your given dates.

USER: It's ok, thanks for your information.

ASSISTANT: Thank you for reaching us.