When the control's value is null (Nothing in VB), the control displays an empty string by default. The NullText property enables the end developer to change the text that is displayed for null values (for example, '(NULL)' or '(none)').
Target Platforms: Windows 10, Windows 8.1, Windows 8, Windows 7, Windows Server 2012, Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2