A dynamic tree control system includes a scripted program sent from a server, to be interpreted by a client browser. The program uses dynamic HTML and includes program code for displaying, under the control of the browser, a tree structure having one or more tree nodes in which at least a portion of data retrieved from the server is represented. The program also includes program code for dynamically altering, in response to some event, the tree structure without further accessing the server. The program also includes an event manager that registers with the browser to be notified upon the occurrence one or more events. The event manager receives notification of the event from the browser, and notifies the layer in which the event originated or took place. A notified layer response to the event, for example, by dynamically altering the tree structure.