I would think it would be ajax myself. I'm not that experience, but I believe you could create the forms and then linking the forms submit to the database and calling it from the database to post the information that was in your form. Kind of like a chat that refreshes itself. A user posts, and it shows up. A user enters something in the form; it shows up. Ajax would be needed for that type of feature I believe.
This way, it wouldn't matter who updated what...it would automatically update as the user entered the information into the form; no matter where they are located at.
Like I said, I'm VERY new to a lot of this scripting, but I'm learning and hoping i"m correct here. I'm sure if I'm not, someone will come around and correct me
Just trying to be helpful. Good luck