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# YUI Library Examples: Drag & Drop: Drag and Drop with the Dragged Element on Top

# Drag & Drop: Drag and Drop with the Dragged Element on Top

This example builds on the basic drag and drop, keeping the dragged element on top of the others by changing its `z-index` property during the drag.

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## Basic Drag and Drop

The YUI Drag and Drop Utility lets you make HTML elements draggable.

For this example, we will enable drag and drop for the three `<div>` elements.

Create the `demo` elements:

<div id="dd-demo-1" class="dd-demo"></div> <div id="dd-demo-2" class="dd-demo"></div> <div id="dd-demo-3" class="dd-demo"></div>

Next, we define a custom drag and drop implementation that extends `YAHOO.util.DD`. Drag and drop exposes many interesting moments that you can use to implement custom functionality. In this example, we override the `startDrag` and `endDrag` moments to adjust the `z-index` property so that the dragged element is always on top.

<script type="text/javascript"> // Our custom drag and drop implementation, extending YAHOO.util.DD YAHOO.example.DDOnTop = function(id, sGroup, config) { YAHOO.example.DDOnTop.superclass.constructor.apply(this, arguments); }; YAHOO.extend(YAHOO.example.DDOnTop, YAHOO.util.DD, { origZ: 0, startDrag: function(x, y) { YAHOO.log(this.id + " startDrag", "info", "example"); var style = this.getEl().style; // store the original z-index this.origZ = style.zIndex; // The z-index needs to be set very high so the element will indeed be on top style.zIndex = 999; }, endDrag: function(e) { YAHOO.log(this.id + " endDrag", "info", "example"); // restore the original z-index this.getEl().style.zIndex = this.origZ; } }); </script>

Now we create the instances of `YAHOO.example.DDOnTop`, passing the element ids or references for our demo elements.

<script type="text/javascript"> (function() { var dd, dd2, dd3; YAHOO.util.Event.onDOMReady(function() { dd = new YAHOO.example.DDOnTop("dd-demo-1"); dd2 = new YAHOO.example.DDOnTop("dd-demo-2"); dd3 = new YAHOO.example.DDOnTop("dd-demo-3"); }); })(); </script>

### YUI Logger Output:

### Drag & Drop Examples:

### More Drag & Drop Resources:

- User's Guide (external)
- API Documentation
- Cheat Sheet PDF (external)

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