You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: Myself Timothy Martin. please help me in making some changes in existing reservation, due to my busy schedule on my previously planned dates.

ASSISTANT: Please give me a moment.

USER: Sure, take your time.

ASSISTANT: Sorry for inconvenience, no reservation found with your name.

USER: Ok, no problem. Thank you for checking.

ASSISTANT: Thank you for contacting us.