<xsl:for-each select="???">  <!-- a1 to a50 -->
select="@*"
selects all the attributes (in whatever order they are in teh input
tree, which may not be the same order as they are in the file, as that
information is lost)

Just as for elements, if the current node is an attribute 
<xsl:value-of select="."/>  gives itsvalue and
<xsl:value-of select="name()"/> gives its name

David