It can be the name of an implemented function or an explicit javascript statement(s). If the name of a function is used, then that event handler may contain 1 parameter. That parameter is the reference to the JavaScript object that represents UltraWebTab. Also see WebForm1.aspx in HTML mode of the ClientSideEvents C# and VB sample applications.
Target Platforms: Windows 10, Windows 8.1, Windows 8, 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