ChangeDialog(xDD,xMSG#,xPR,x00)

Change or delete the dialog inside a dialog box.

DD = Dialogue Box ID.

Starts at x01, IDs based on age of oldest currently-existing dialogue box.

MSG# = Message ID.

ID of the message replacing the previous one.  Use xFFFF to close the Dialogue Box instead.

PR = Portrait Row.

Row parameter when forcing a WLDFACE.BIN Portrait.  Must be paired with {51}PortraitCol to use, see that command for more information.