You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you today?

USER: I want to change my existing reservation. Due to heavy rains my cricket match got postponed. Can you please help me out?

ASSISTANT: Sure, may I know your name to check for the previous reservation?

USER: I have reserved my previous ticket with name Jack Smith.

ASSISTANT: Please allow me a moment. Jack Smith, there is no reservation found under your name.

USER: Ok, fine thanks for your information.

ASSISTANT: Thank you for contacting us.