You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Jacob Thompson.

ASSISTANT: How may I assist you today?

USER: I want to change my existing reservation, due to health issue. Can you help me in my changing reservation?

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: Please wait for some time.

USER: Sure, I will wait for your response.

ASSISTANT: Thanks for being patient, there is no reservation found on your given name.

USER: Not an issue. Thank you for your kind information.

ASSISTANT: Thank you for availing us.