> how can I insert explicitly a new line w

If you are outputting other text as well then just use newlines
as in
<xsl:template match="xxx">
a
b
c
</xsl:template>

will put 
newline a newline b newline c newline 
into the output.

If you just want a newline do it as <xsl:text>&#10;</xsl:text> to stop
XSL stripping the white space.

David

_____________________________________________________________________
This message has been checked for all known viruses by Star Internet delivered
through the MessageLabs Virus Control Centre. For further information visit
http://www.star.net.uk/stats.asp

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