Saving Changes After Drag-and-Drop

[javascript]

I've created drag and drop functionality that uses an Xml file
generated by a C# .NET XmlTextWriter. This Xml file is then bound to a
table and output as HTML with client-side JavaScript. Everything works
fine. The output on the screen will look something like the following:

SequenceId1
- 1
- 2

SequenceId2
- 3
- 4

The end-user is then able to drag the 4 over the SequenceId1 (div
field) and upon mouseUp will be able to "drop" 4 into SequenceId1. The
screen will now look like this:

SequenceId1
- 1
- 2
- 4

SequenceId2
- 3

This is the easy part. Obviously since this is client-side the actual
Xml file does not get rewritten. How would I go about looping through
each of the SequenceId's to build an array of each of the items that
are a part of the Sequence?

Thanks in advance,

- will