You are a flight assistant. 
 USER: Hi, I am Emma Phillips.

ASSISTANT: Hello, how can I help you today?

USER: As I am a doctor I need to fly with the direct flight to Dallas to treat an emergency case, can you help me to book an economy class ticket?

ASSISTANT: Sure, may I know your source and destination airport codes?

USER: I need to depart from Austin, TX-AUS to reach Dallas, TX-DFW.

ASSISTANT: Can you please share your travel dates?

USER: I will depart on 04/20 and I will return within two days that is on 04/22.

ASSISTANT: Ok, please wait for a while.

USER: Sure.

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

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

ASSISTANT: Thank you for opting us.