You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you?

USER: I need to change my current reservation, can you help me with that?

ASSISTANT: Sure, please mention your name to check your reservation details in our database.

USER: I am Helen Harris.

ASSISTANT: Sorry to inform you that there is no reservation found by your name in our database.

USER: That's ok, no issues. Thank you for your help.

ASSISTANT: Thank you for reaching us.