username() does not always evaluate in infopath

I have a testbox in my infopath form which is set to open in a browser. The value of the textbox is set to the username() formula.

When I cre开发者_开发问答ate a new form, the username() formula evaluates to the logged in's username, but the textbox is blank when an existing form is opened. This is fine, but should I expect the same behavior when the formula username() is used in a conditional statement?

Check the Textbox properties whether the

"Update this value when the result of the formula is reclaculated"

check box has been ticked. this should mean that the username will be updated when the form is opened by other people. as for the conditional statement I would expect the the Username to return the username when ever it is recacluated.

Also note that the Username depends on the security set up of you form. Have a look at UserName Property to verify the security requirements against the Microsoft Documentation.