Understanding the <span datafld="value"> stuff

Needless to say I am new to XML programming and appreciate any pointers.

Here's what I have so far. I have a table with a datasrc="#xmldso_list". I am then putting the values from the XML file to the table like this:


<td ><span datafld="v1"></span></td>
<td ><span datafld="v2"></span></td>
...
<td ><span datafld="v7"></span></td>

That works fine, and dynamically generates a table displaying XML content. Here's what I am trying to do. The v1 values are the names, for instances RED, BLUE, GREEN, etc... I may have several rows of the same name, looking like this:

-----------------------
RED xxx xxx xxxxx xxx
RED xxx xxx xxxxx xxx
BLUE xx xxx xxxxx xxx
BLUE xx xxx xxxxx xxx
BLUE xx xxx xxxxx xxx
GREEN x xx xxxx xxx

What I want to do is to place a separation between the rows as the name changes, as this:

-----------------------
RED xxx xxx xxxxx xxx
RED xxx xxx xxxxx xxx
-----------------------
BLUE xx xxx xxxxx xxx
BLUE xx xxx xxxxx xxx
BLUE xx xxx xxxxx xxx
-----------------------
GREEN x xx xxxx xxx

How could I check to see if the v1 in the previous row is different, and insirt a separator line?

Many thanks for your help!