Drag and Drop extension

Left tree - drag out allowed, drag in denied.
drop as child
drop as sibling
Source
<link rel="STYLESHEET" type="text/css" href="../../codebase/dhtmlxtree.css">
<script  src="../../codebase/dhtmlxcommon.js"></script>
<script  src="../../codebase/dhtmlxtree.js"></script>    
Left tree - drag out allowed, drag in denied.    
<table>
    <tr>
        <td>
            drop as child
            <div id="treeboxbox_tree" style="width:250px; height:218px;background-color:#f5f5f5;border :1px solid Silver;"/>
        </td>
        <td style="padding-left:25" valign="top">
            drop as sibling
            <div id="treeboxbox_tree2" style="width:250px; height:218px;background-color:#f5f5f5;border :1px solid Silver;"/>
        </td>
    </tr>
</table>
<br>
<script>tree = new dhtmlXTreeObject("treeboxbox_tree", "100%", "100%", 0);
tree.setSkin('dhx_skyblue');
tree.setImagePath("../../codebase/imgs/csh_yellowbooks/");
tree.enableDragAndDrop(true);
tree.enableSmartXMLParsing(true);
tree.loadXML("../common/tree_05_drag_n_drop.xml");
tree2 = new dhtmlXTreeObject("treeboxbox_tree2", "100%", "100%", 0);
 
tree2.setSkin('dhx_skyblue');
tree2.setImagePath("../../codebase/imgs/csh_yellowbooks/");
tree2.enableSmartXMLParsing(true);
tree2.enableDragAndDrop(true);
tree2.setDragBehavior("sibling");
tree2.loadXML("../common/tree_05_drag_n_drop.xml");
function my_func(id_drag, id_landing) {
    return false;
}
tree.setOnDragIn(my_func);</script>