Group and sort nodes by attribut in child node

Hi everyone,

I need to group nodes by attributes which are in a child node. To be more
specific, this is my XML:

<record>
B B  <column field="keyword" value="A">
B B  <column field="Start_Date" value="23.12.2010">
B B  <column field="Group" value="">
</record>
<record>
B B  <column field="keyword" value="B">
B B  <column field="Start_Date" value="24.12.2010">
B B  <column field="Group" value="X_Group">
</record>
B B  <column field="keyword" value="D">
B B  <column field="Start_Date" value="25.12.2010">
B B  <column field="Group" value="">
</record>
<record>
B B  <column field="keyword" value="C">
B B  <column field="Start_Date" value="23.12.2010">
B B  <column field="Group" value="X_Group">
</record>
</record>
B B  <column field="keyword" value="D">
B B  <column field="Start_Date" value="25.12.2010">
B B  <column field="Group" value="Y_Group">
</record>
<record>
B B  <column field="keyword" value="E">
B B  <column field="Start_Date" value="26.12.2010">
B B  <column field="Group" value="Y_Group">
</record>
<record>

The result should be like this:
B  A - 23.10.2010
B  X_Group
B B B  C - 23.10.2010
B B B  B - 24.12.2010
B  D - 25.10.2010
B  Y_Group
B B B  D - 25.12.2010
B B B  E - 26.12.2010

I want to group by the value of the group field in the column node and
everything should be sorted by start_date. The name of the group (e.g.
X_Group) should start a group-block, followed by the record nodes which belong
to the group value.
Another problem is that i donB4t know the group value in advance, because they
can be set to whatever the user want.

If there is a solution which i didnB4t found, could you please point me in the
right direction?

Thanks in advance.

Best,
Jens
___________________________________________________________
SMS schreiben mit WEB.DE FreeMail - einfach, schnell und
kostenguenstig. Jetzt gleich testen! http://f.web.de/?mc=021192