A method of displaying messages on handheld devices (10). The device (10) displays messages in a scrollable viewport (74) of vertically arranged fields (76). Date separators (80) inserted into the vertically arranged list of messages to enable the user to associate the messages with a date. The date separators (80) have ''sticky'' operation, meaning that the device (10) ensures a date separator (80) always appears within the viewport (74), even when the viewport (74) has been scrolled to the middle of a long list of messages all associated with the same date. The device (10) may ensure that the top field (74a) of the viewport (74) always contains a date separator (80) associated with the message immediately below.