Sri,
You have to have an orchestration variable called filename to all you to use vars in the expression window. Furthermore, if you are trying to access it inside a scope (your ‘Transaction_2’), the variable will need to be created inside the scope, rather than the ‘outer’ orchestration.
Because the variable is already declared in the orchestration/scope, you can then use it as:
filename = “c:\\employee.xml”;
However, I have to question why you are writing an Xml file from within an expression shape? Use a Send Port with the FILE adapter and get all of the sexy enterprise features that you won’t have with your block of code, such as retries, suspended messages, transactional support etc.
If you need clarification on any of the above, drop me a line.
Cheers, Nick.