You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I serve you the best today at this moment?

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

ASSISTANT: Sure, I will help you with that.

USER: Thank you.

ASSISTANT: On which name your previous ticket has been reserved?

USER: I am Brenda Martinez.

ASSISTANT: Please give me a moment, I will check and get back to you.

USER: Ok.

ASSISTANT: Unfortunately there is no reservation found with your provided name in our data base.

USER: No problem, thanks for your information.

ASSISTANT: Thank you for connecting with us.