jQuery draggable plugin

jquery.draggable.js

// jQuery draggable plugin
(function($) {
    $.fn.draggable = function(options) {
        var $handle = this,
            $draggable = this;

        options = $.extend({}, {
            handle: null,
            // allow children to be a handle
            handleChildren: true,
            cursor: 'move'
        }, options);

        if( options.handle ) {
            $handle = $(options.handle);
        }

        $handle
            .css({
                '-webkit-user-select': 'none',
                '-moz-user-select': 'none',
                '-ms-user-select': 'none',
                'user-select': 'none',
                'cursor': options.cursor
            })
            .on("mousedown", function(e) {
                var x = $draggable.offset().left - e.pageX,
                    y = $draggable.offset().top - e.pageY,
                    z = $draggable.css('z-index');

                // if click on children and disabled handle children
                if ( !options.handleChildren && e.target != this ) {
                    return;
                }

                $draggable.css('z-index', 100000);

                $(document.documentElement)
                    .on('mousemove.draggable', function(e) {
                        $draggable.offset({
                            left: x + e.pageX,
                            top: y + e.pageY
                        });
                    })
                    .one('mouseup', function() {
                        $(this).off('mousemove.draggable');
                        $draggable.css('z-index', z);
                    });

                // disable selection
                // e.preventDefault();
            });

        return this;
    };
})(jQuery);