# OnClientNodeDragStart

The **OnClientNodeDragStart** client-side event is called each time the user begins to drag a node.

The event handler receives parameters:

1. The TreeView\*\* instance that fired the event.

2. Event arguments with functions:

* **get_node()** retrieves a reference to the clicked on node.

* **set_cancel()** - call this function to specify whether the event should be canceled (true) or not (false).

* **get_domEvent()** retrieves a DOM event object of the node dragging.

* **get_htmlElement()** retrieves the <SPAN> element of the dragged node.

* **get_sourceNodes()** returns an array of all the nodes being dragged (Useful when **MultipleSelect** is *True*).

The example below demonstrates getting the current x and y coordinates of the mouse while the node is being dragged.

```JavaScript
function ClientNodeDragStart(sender, eventArgs) {
    var node = eventArgs.get_node();
    if (node.get_level() == 0) {
        var myDiv = document.getElementById("myDiv");
        myDiv.innerHTML = "Cannot drag " +
   node.get_text() +
   " at level " +
   node.get_level();
        eventArgs.set_cancel(true);
    }
}
```

## See Also

* [OnClientNodeDropped](https://www.telerik.com/products/aspnet-ajax/documentation/controls/treeview/client-side-programming/events/onclientnodedropped)

* [OnClientNodeDropping](https://www.telerik.com/products/aspnet-ajax/documentation/controls/treeview/client-side-programming/events/onclientnodedropping)

* [OnClientNodeDragging](https://www.telerik.com/products/aspnet-ajax/documentation/controls/treeview/client-side-programming/events/onclientnodedragging)

* [RadTreeNode](https://www.telerik.com/products/aspnet-ajax/documentation/controls/treeview/client-side-programming/objects/radtreenode)