counting equal entries

Hi all,
I try to create an index page from a document. The idea behind is to
collect a certain word and list it with *all* occurences in the
document, like

foo .... 12, 23, 45
bar .... 2, 5, 88

and so on. I have a XML document which contains entries with different
classes (Java classes).
I have a XSL stylesheet which collects all entries in a sorted order.
But there is one separate entry for each occurence:

foo ... 12
foo ... 23
foo ... 45
bar ... 2

and so on.

Code follows:

<xsl:for-each select="key('index-key', $lower-alphabet)">
 <xsl:sort select="@name" case-order="lower-first"/>
 <xsl:call-template name="display-index-item">
  <xsl:with-param name="item" select="." />
 </xsl:call-template>
</xsl:for-each>

The $lower-alphabet is only a variable containing all lower letters.
How can I pass an indicator to the template "display-index-item" where
I can decide if an entry has the same name as the previous one?

TIA,
Ralf.