testing for child node and counting

Hi, I have an xml like this:

<Orders>
    <Row att="...">
        <field_a>...</field_a>
        <field_b>...</field_b>
    </Row>
    <Row att="...">
        <field_a>...</field_a>
        <field_b>...</field_b>
        <field_c>...</field_c>
    </Row>
    ...
</Orders>


1. I want to go through each <row> and create 
   an html table row only if <row> contains a
   <field_c> child. I've tried this but it 
   didn't work:

<xsl:for-each select="Orders/Row">
  <xsl:if text="Orders/Row/field_c">

     <tr>
       <td><xsl:value-of select="field_c"/></td>
     </tr>

  </xsl:if>
</xsl:for-each>

2. I want to print at the top of the html table
   the number of <row>s that have a <field_c>
   child.

Thanks in advance for any help.
-alex

__________________________________________________
Do You Yahoo!?
Send FREE Valentine eCards with Yahoo! Greetings!
http://greetings.yahoo.com

 XSL-List info and archive:  http://www.mulberrytech.com/xsl/xsl-list