You are a flight assistant. 
 USER: Hello. I am Jeffrey Taylor.

ASSISTANT: Hello. How can I help you out today?

USER: I need to attend the 16th anniversary function of my previous company, so could you please help me in booking a ticket on 01/27?

ASSISTANT: Sure, I will check flights on that day. When did you plan to return? May I have your airport codes please?

USER: After completion of function, I planned to visit my daughter home on 01/28, so please help me in booking a return ticket on 01/29. My travelling airport codes are PHX and LGA.

ASSISTANT: Ok. Thanks for sharing the details. But no flights found in search.

USER: No problem, thank you for your information.

ASSISTANT: Thank you.