how to access json data mule esb

i want to access json data generated from the sync flow into an async flow. I am getting json data from sync flow correctly and i want to fetch certain attribute value from that my json data is as follows : ``` {"data" : [{"in_timestamp":"2012-12-04","message":"hello","out_timestamp":null,"from_user":"user2","ID":43,"to_user":"user1"}]} and to user is #[json:to_user]} ``` I want to access to_user attribute from this json format. I have tried using `#[json:to_user]` but it simply prints it as a string and doesnt return any value. Please help. Thanks in advance.