Editable Outliner w/ drag & drop in browser?

[David Winter]

I have a particular application that requires reordering objects by
drag and drop, and I would like to do this with a web frontend.

To be more precise: There are headlines and paragraphs stored in a
database, but forcing the editors to put them into a certain sequence
by entering a sequence number for every item (or clicking on an "up"
button fifty times) would be much too cumbersome. So I want to give
them an outline view of the text instead.

Now let's assume we build a web page where every head or paragraph is
represented by a <DIV> with one line of text. The user should now be
able to move a paragraph or a group of paragraphs somewhere else by
dragging this particular DIV with the mouse. When he releases the
mouse, the DIV appears at the new position, and a hidden attribute for
all <DIV>s (i.e., their "Sequence" ID) is modified accordingly. So when
the surrounding form is submitted to the server, this attribute is
updated.

Is this possible using the DOM and a modern browser, especially when we
are talking about a lot (100 - 200) of items?

I have seen some impressing stuff done with the DOM, but I assume this
is a bit much. Correct me if I'm wrong ...