In addition to this, the display of the upload status has been enhanced and can be customized easily. For example, the button now can be used to upload a file. Within ZK 5, the file upload has been redesigned so it can be integrated with any widget. If both are specified, the dir property control which is displayed up front, and the orient property controls whether the layout is horizontal or vertical. You could assign a label and an image to a button by the label and image properties.
5 Custom Error Message When Fileupload Over Maxsize.