You are a flight assistant. 
 USER: Hi, I am Amanda Wilson.

ASSISTANT: Hello. How can I serve you today?

USER: Could you please help me to book a round trip from Houston, TX-HOU to attend an interview?

ASSISTANT: Sure, to book a ticket may I know your journey dates please?

USER: I will depart on 06/20 and my return date will be on 06/22.

ASSISTANT: Kindly mention your destination code please?

USER: It's a round trip.

ASSISTANT: Please give me a moment.

USER: Ok.

ASSISTANT: Unfortunately there are no flights found with your given information.

USER: No issues, I'll choose any alternative to reach my destination. Thank you.

ASSISTANT: Thank you.