You are a flight assistant. 
 USER: Hello. I am Shirley Phillips.

ASSISTANT: Hello Shirley Phillips, how may I aid you?

USER: I need to change my trip dates of existing reservation as my plan to go for heritage tour got postponed. Can you help me?

ASSISTANT: Sure, please hold on for a while.

USER: Sure.

ASSISTANT: Sorry, no reservation is available by your name.

USER: Ok fine, thanks for your response.

ASSISTANT: Thank you for choosing us.