Given the task definition and input, reply with output. In this task, you're given a dialogue between a customer and a flight booking agent with a gap in the conversation. Your job is to find the answer of the previous dialogue. Avoid using irrelevant extra information while creating the answer. The answer should be relevant to the question before the blank. If you fill the blank with a question, it should have an answer from the agent in the given dialogue. Fill the gap marked with underline.

customer: Hello, I am Steven Miller. 
 agent: Hello. How can I help you? 
 customer: I would like to attend my friend birthday, can you please book me a ticket? 
 agent: Sure, may I know your travelling dates? 
 customer: My travelling dates are from 12/17 to 12/19. 
 __ 
 customer: My preferable airport codes are from SFO to IAH. 
 agent: Do you have any connection limit? 
 customer: Yes, I have one connection limit. 
 agent: Please wait a while. 
 customer: Ok. 
 agent: Thanks for being waiting. We found a Spirit airline,flight number:1008 and the price is 100. 
 customer: Ok, book this flight. 
 agent: Your flight ticket has been confirmed. 
 customer: Thanks for booking. 
 agent: Thank you for consulting us.

agent: Please let me know your airport codes?