>       <!-- I need an additional parameter for the dataType. 
> It is defined in the child tag with different data type names -->
>       <!-- <xsl:with-param name="data_type" select="."/>-->



If I understand what you are asking, simply:

 <xsl:with-param name="data_type" select="local-name(*)"/>

gets the name of an unknown child element;

 <xsl:with-param name="data_type" select="*"/>

gets the value of an unknown child element.

"." selects self::node(), not child::node().  An empty path signifies
children, so you would choose the value of an unknown child node with "*",
the first unknown child with "*[1]".

This is elementary.

-----------------------------------
Mike Haarman,
XSL Developer,
Internet Broadcasting Systems, Inc.