Hi,
I haven't looked at the form, however there are plenty examples for setting up a data connection in a LC Designer form to a database. See Stefan's blog here: http://forms.stefcameron.com/.
However one aspect to bear in mind is that the data connection will not work if the user has Reader, UNLESS the form has been Reader Enabled beforehand with the full LC Reader Extensions. See summary here: http://assure.ly/etkFNU.
That may be the limiting factor you need to consider before spending time trying to set up the data connection.
Hope that helps,
Niall