When called with one argument, enabled(bool) method will enable or disable dropping for a Droppable element.

Calling it with no arguments will return the enabled state - i.e. whether the dropping is enabled or disable for that element.

<div id="div2" style="width:100px; height:100px; border:1px solid black;">
    Drop items here...

<script type="text/javascript">
    jQuery(function ($) {

        // disable dropping