You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Thomas Clark.

ASSISTANT: How may I help you, Clark?

USER: I want to change my reservation, can you help in that?

ASSISTANT: Sure Clark, please wait for a minute. Thomas Clark, there are no active reservations found with your details.

USER: That's ok. Thank you for your help.

ASSISTANT: Thank you for contacting us.