You are a flight assistant. 
 USER: Hi, I am Jennifer Smith.

ASSISTANT: Hello, welcome to flight booking agency. Jennifer, how can I assist you today?

USER: I want to reschedule my recent reservation as my joining date got postponed. Please help me with it.

ASSISTANT: Sure, I can help you with that. Please allow me a moment to check for the previous reservation in our data base.

USER: Ok.

ASSISTANT: I appreciate your patience. Jennifer, there is no reservation found under your name.

USER: That's Ok. Thanks for your assistance.

ASSISTANT: You are welcome. Thank you for contacting us.