Monitor partial postback using fiddler

Monitor partial postback using fiddler

I have a test page. The test page simply has a textbox and a button. In
between them, I have added a script manager, update panel and another
textbox and button. I also set that the trigger for the update panel only
can be triggered by the inner button. And the update mode for the update
panel is conditional.
I use fiddler to monitor whenever I have triggered the inner button
(button inside the update panel). And I found out that, it shows several
name value in the Response body. 1. ScriptManager1 2. _EventTarget 3.
_EventArgument 4. Outer textbox 5. Inner textbox 6. _viewstate 7.
_eventvalidation 8. _asyncpost 9. inner button
I'm wondering, since this is just a partial postback for the inner
textbox, is it normal for the outer textbox to be appeared in the response
body?