You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: My name is Debra Walker.

ASSISTANT: How can I help you?

USER: Due to health issues, I need to change my recent reservation. Please help me in that.

ASSISTANT: Ok, let me check your reservation details in our database.

USER: Ok.

ASSISTANT: Sorry, we couldn't found any flights for you.

USER: No problem, thanks for your information.

ASSISTANT: Thank you for reaching us.