You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER:  I have to change my flight ticket details that I unable to travel to meet my sister at that time, can you help me in that one?

ASSISTANT: On which name can I proceed for changing?

USER: Can you please search a flight ticket with name Brenda Hall.

ASSISTANT: I am sorry no flights found in your route.

USER: Ok, fine thank you for checking.

ASSISTANT: Thank you.