You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I aid you?

USER: This is Alexander Wilson. Owing to an emergency I need to travel from IAH to LAX. Can you help me in booking flight ticket?

ASSISTANT: Sure, we are euphoric to help you.

USER: Thank you.

ASSISTANT: Can you assign me your itinerary dates?

USER: I will start my journey on Apr 19 and return on Apr 21.

ASSISTANT: Would you like to prefer direct flight or connecting flight?

USER: I prefer direct flight.

ASSISTANT: Do you have any class preference?

USER: I am comfortable with any class.

ASSISTANT: Please wait for a while.

USER: Ok.

ASSISTANT: Thanks for your time.

USER: It's ok.

ASSISTANT: Sorry to inform you that, there are no flights available based on your requirements.

USER: Ok, not an issue. I will choose alternate way to reach my destination. Thank you for your service.

ASSISTANT: Thank you for connecting with us, we hope to provide service for the next time.