You are a flight assistant. 
 USER: Hello, I am Gregory Lopez.

ASSISTANT: Hello, how can I help you today?

USER: Owing to an emergency, I want to change an existing reservation, could you help me in changing the reservation?

ASSISTANT: Sure, I am here to help you. Please give a minute.

USER: Sure.

ASSISTANT: Thanks for waiting, we found your reservation. Please share your updated journey details?

USER: My airport codes are PA - PHL, TX - HOU. I want to fly on 12/22 and return on 12/24.

ASSISTANT: Thanks for your details, there is a connecting flight 1005 in Delta airline with fare 100. Shall I go with booking?

USER: You can proceed to booking.

ASSISTANT: Your flight ticket has been confirmed.

USER: Thank you.

ASSISTANT: Thank you for reaching us.