[Name] joinid [Required] false [Type] ECMAScript Expression [Default Value] none [Valid Values] (valid connection, conference, or dialog ID) [Description] 
An ECMAScript expression that identifies a connection, conference, or dialog ID that the new call must be joined to. This is equivalent, from the perspective of the CCXML application, to performing a immediately following the . However, platforms may use knowledge about the connection/conference/dialog to which the new call will be connected to optimize the call creation process. If the attribute value is invalid an error.semantic event must be thrown.