You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you for the day?

USER: I have planned for the trip with my friends, but some of my friends are unable to come in the planned dates, so we all changed our trip. So can you help me to change the existing reservation.

ASSISTANT: Sure, let me know your name for checking?

USER: My name is Pamela Hernandez.

ASSISTANT: Sorry Pamela, no reservation found by your name. Thanks for reaching us.

USER: It's ok, thank you for the information.

ASSISTANT: Have a great day.