answer: Jane wants to speak to Mr. Wang but he is not available. Jane needs Mr. Wang to call back, so she leaves her number to #Person2#.
documents: #Person1#: This is frank speaking, may i ask who is calling?
  #Person2#: This is Jane, I'd like to speak to Mr. Wang, please.
  #Person1#: I'm sorry, he is not here at the moment. He has gone to the International Business Center.
  #Person2#: When do you expect him back?
  #Person1#: I'm not sure, he didn't say when he wound return. If you'd like. you can leave him a message until he is back to you until the moment it's free.
  #Person2#: Yes, thank you. When he gets back, please just let him know that jane called. And i need him to call me back.
  #Person1#: Does he have your number?
  #Person2#: Yes, he does. But i give it to you again. 5264453 6
  #Person1#: That was 5264453 6, right?
  #Person2#: Yes, thank you very much.
  #Person1#: You are welcome.