onChange does not funtioning?

Hi,
I have:

        <form action="Default.aspx"    runat="server">


<select name="SelectCategories">
                  <xsl:attribute name="onChange">form.submit()</xsl:attribute>
                  <xsl:for-each select="document('../content/en//categorycodes.xml')/catcodes/category">
                    <option>
                      <xsl:attribute name="value">
                        <xsl:value-of select="@code"/>
                      </xsl:attribute>

                      <xsl:value-of select="."/>
                    </option>
                  </xsl:for-each>
                </select>



</form>

onChange is not reacting.
Should I use javascript instead?
Thanks
Nenad