Reply to comment
Converts a screen name or e-mail address to a user value. A "user" is an individual with whom you've shared your application. You'd translate something like an e-mail address into a user value so that QuickBase recognizes the user. When you do so, you can take advantage of user fields to design permissions and/or views. For example, show a user only those tasks that have been assigned to her.
ToUser([Email Address]) takes the values in the Email Address field and returns their corresponding user values. ToUser("jsmith") returns the user with the screen name "jsmith". ToUser("firstname.lastname@example.org") returns the user possessing that e-mail address.