Extract data from XML field in SQL Server 2005 table

I have a sql server table

CREATE TABLE [dbo].[XmlImportTest](

                [xmlFileName] [varchar](300) COLLATE Latin1_General_CI_AS NULL,

                [xml_data] [xml] NULL

) ON [PRIMARY]

which contains xml

<form name="esb_recording" application-name="esb_recording" application-id="102" document-id="441" producer="Penvision Formidable Application Server" export-time="2011-04-29T15:03:17+01:00" first-page="83.17.3.121" last-page="83.17.3.121">
  <submit penid="0x000001e3000214ed" penid-dashed="ATD-AAF-BUX-QE" first-stroke-time="2011-04-29T14:42:07+01:00" last-stroke-time="2011-04-29T14:43:42+01:00" total-time="0:01:35" email="cryan@futurerange.ie" phone="+353868795846" />
  <field type="boxed" name="site_code" normalized-score="0.512" resemblance-score="0.579">D0173TPI</field>
  <field type="boxed" name="mon_day_1" normalized-score="0.726" resemblance-score="0.747">4567895</field>
  <field type="boxed" name="tues_day_1" normalized-score="0.697" resemblance-score="0.816">6432567</field>
  <field type="boxed" name="wed_day_1" normalized-score="0.624" resemblance-score="0.64">8943245</field>
  <field type="boxed" name="thur_day_1" normalized-score="0.634" resemblance-score="0.554">6789432</field>
  <field type="boxed" name="fri_day_1" normalized-score="0.718" resemblance-score="0.898">5678943</field>
  <field type="boxed" name="sat_day_1" normalized-score="0.753" resemblance-score="0.843">2456789</field>
</form>

How can I extract say the field value for the site_code etc using SQL?