You are saying to write "msg" before the text I was writing and realized that I wanted a message box? (sorry, non native english speaker here)
Suposing that's what you meant, it didn't work, at least in Pd-extended 0.42.5

Caio Barros

2011/3/10 Ivica Ico Bukvic <ico@vt.edu>
Prepend the contents with msg (don't forget the space between msg and contents) then activate object to be recreated.

Ico

Caio Barros <caio.barros@gmail.com> wrote:

>Some of you probably went to the same problem I do.
>Sometimes I automatically press Ctrl+1 and start writing stuff. Them I
>realize that what I needed was a Message Box (Ctrl+2) and not the Object
>Box.
>If it was possible to change the box type without changing its content it
>would be great.
>I know that I can edit the pd file in a text editor to do that. But often
>this takes more time than to create a message box and write everything
>again.
>
>Caio Barros
>
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