Q:

XSLT: how to ignore unnecessary white space? 

Given this example XML file:
<doc>
<tag>

    Hello ! 

</tag>
<tag>
    My
    name
    is
    John
</tag>
</doc>

And the following XSLT sheet:
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:template match="/"> 
    <xsl:for-each select="doc/tag">
        <xsl:value-of select="."/ >
    </xsl:for-each>
</xsl:template> 
</xsl:stylesheet>

How should I change it in order to ignore line feeds and convert any group of white-space characters to just one space in the items?  In other words, I would like to obtain:
Hello! 
My name is John

Without all those those silly line feeds. ... the question is how. 
Thanks in advance ! 

A:

<xsl:template match="tag">
  ...
  <xsl:value-of select="normalize-space(.)" / >
  ...
</xsl:template>

In fact, there is a good post about it.