You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Lisa Harris.

ASSISTANT: How can I help you?

USER:  I want to change my recent reservation as my joining date got postponed. Can you help me in changing?

ASSISTANT: Sure, I am here to help you. Please stand by.

USER: Ok.

ASSISTANT: Thank you for waiting. Sorry to say no reservation found on your name.

USER: Ok, no issues. Thanks for the help.

ASSISTANT: Thank you for reaching us, have  a nice day.