Script code for Sub window error message capture

Hello Experts,

I am facing issue while capturing error message which is in window 2. You can see below screen shot for your reference.

I got the code as follows " Session.FindById("wnd[2]").Text " Which is juts giving Text as "error". I need complete Error message to be captured.

I even tried to use session.findById("wnd[2]/tbar[0]/btn[0]").text which results in capturing empty.

Can some one help me by providing this single line code for capturing second window message.

Thanks

Jim