The following events are available in dhtmlxTree:
-   Drag-and-Drop Events: - 
-   onBeforeDrag-  - occurs when item's dragging starts (the item is selected and the mouse is moving); 
 
-   onDrag-  - occurs when the item was dragged and dropped on some other item, but before item's moving is processed; 
 
-   onDragIn-  - occurs when the item is dragged over some target the item can be dropped to; 
 
-   onDrop-  - occurs when drag-and-drop had already been processed; also occurs when the nodes are moved programmatically; 
 
 
-   Editing Events: - 
-   onEdit-  - occurs on 4 different stages of edit process: before starting of editing (can be canceled), after starting of editing, before editor's closing (can be canceled), after editor's closing; 
 
- 
-   onCheck-  - occurs immediately after an item in the tree was checked|unchecked; 
 
 
-   Loading Events: - 
-   onXLS-  - occurs when  XML-  parsing starts; 
 
-   onXLE-  - occurs when  XML-  parsing is over, new items are already available in the tree; 
 
 
-   Mouse Events: - 
-   onMouseIn-  - occurs when the mouse pointer is hovered over an item; 
 
-   onMouseOut-  - occurs when the mouse pointer is moved out of item's area; 
 
 
-   Opening Events: - 
-   onOpenStart-  - occurs right when an item in the tree starts to open, but before this item opens. This event is also available for “unclosable” nodes and nodes without open|close functionality - in that case result of the function will be ignored; 
 
-   onOpenEnd-  - occurs right when an item in the tree has already become open. Event also raised for “unclosable” nodes and nodes without open/close functionality - in that case result of function will be ignored. 
 
-   onDblClick-  - occurs right when a tree item was double clicked, but before default onDblClick functionality is processed; 
 
-   onOpenDynamicEnd-  - occurs when openItemsDynamic() method loads and opens the required hierarchy of items; 
 
 
-   Right Click Events - 
-   onRightClick- - occurs when the user clicks the right mouse button; 
 
 
-   Selection Events - 
-   onClick-  - occurs when the text part of a tree item was clicked, but after default onClick functionality was processed; 
 
-   onSelect-  - occurs when the selection in the tree was changed. 
 
 
 
The user can add any user-defined handler to available events. To do this he can use attachEvent() method with the following parameters:
              tree.attachEvent(evName, evHandler);
 
Several handlers can be attached to one and the same event, and all of them will be executed.
Note: the names of the events are case-sensitive.
There is a simple way of removing an event-handler:
          tree.detachEvent(id); // unique id of the event handler