customer: Hello. 
 agent: Hello. 
 customer: My name is William Collins. 
 agent: How can I help you today? 
 customer: I have a business meeting in Los Angeles. Can you help me for booking a flight? 
 agent: Sure, can you please share your travel dates? 
 customer: My travelling dates are from 02/22 till 02/24. 
 agent: Ok, may I know your airport codes? 
 customer: My travelling airport codes are from DCA to LAX. 
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 customer: It's ok, thank you for your information. 
 agent: Welcome, have a nice day.
agent: Sorry, no flights are available on your route.