Hello,

B I'm not sure whether I'm being dumb or not here but I'm stuck on converting
a
flat structure to a nested structure.

the flat structure is like this:-

<?xml version="1.0 " encoding="US-ASCII"?>
<doc>
B  <ch id="1o1">
B  B  <sec id="sec1o1o1" fpage="3" lpage="5" />
B  B  <sec id="sec1o1o1o1" fpage="3" lpage="3"/>
B  B  <sec id="sec1o1o1o2" fpage="3" lpage="4"/>
B  B  <sec id="sec1o1o1o3" fpage="4" lpage="4"/>
B  B  <sec id="sec1o1o1o4" fpage="4" lpage="5"/>
B  B  <sec id="sec1o1o1o5" fpage="5" lpage="5"/>
B  B  <sec id="sec1o1o2" fpage="5" lpage="7"/>
B  B  <sec id="sec1o1o2o1" fpage="5" lpage="5"/>
B  B  <sec id="sec1o1o2o2" fpage="5" lpage="5"/>
B  B  <sec id="sec1o1o2o3" fpage="5" lpage="6"/>
B  B  <sec id="sec1o1o2o4" fpage="6" lpage="7"/>
B  B  <sec id="sec1o1o2o4o1" fpage="6" lpage="6"/>
B  B  <sec id="sec1o1o2o4o2" fpage="6" lpage="6"/>
B  B  <sec id="sec1o1o2o4o3" fpage="6" lpage="7"/>
B  B  <sec id="sec1o1o3" fpage="7" lpage="10"/>
B  B  <sec id="sec1o1o3o1" fpage="7" lpage="7"/>
B  B  <sec id="sec1o1o3o1o1" fpage="7" lpage="7"/>
B  </ch>
</doc>

I would like to get to

<?xml version="1.0" encoding="US-ASCII"?>
<doc>
B  <ch id="1o1">
B  B  <sec id="sec1o1o1" fpage="3" lpage="5">
B  B  B  <sec id="sec1o1o1o1" fpage="3" lpage="3"/>
B  B  B  <sec id="sec1o1o1o2" fpage="3" lpage="4"/>
B  B  B  <sec id="sec1o1o1o3" fpage="4" lpage="4"/>
B  B  B  <sec id="sec1o1o1o4" fpage="4" lpage="5"/>
B  B  B  <sec id="sec1o1o1o5" fpage="5" lpage="5"/>
B  B  </sec>
B  B  <sec id="sec1o1o2" fpage="5" lpage="7">
B  B  B  <sec id="sec1o1o2o1" fpage="5" lpage="5"/>
B  B  B  <sec id="sec1o1o2o2" fpage="5" lpage="5"/>
B  B  B  <sec id="sec1o1o2o3" fpage="5" lpage="6"/>
B  B  B  <sec id="sec1o1o2o4" fpage="6" lpage="7">
B  B  B  B  <sec id="sec1o1o2o4o1" fpage="6" lpage="6"/>
B  B  B  B  <sec id="sec1o1o2o4o2" fpage="6" lpage="6"/>
B  B  B  B  <sec id="sec1o1o2o4o3" fpage="6" lpage="7"/>
B  B  B  </sec>
B  B  </sec>
B  B  <sec id="sec1o1o3" fpage="7" lpage="10">
B  B  B  <sec id="sec1o1o3o1" fpage="7" lpage="7">
B  B  B  B  <sec id="sec1o1o3o1o1" fpage="7" lpage="7"/>
B  B  B  </sec>
B  B  </sec>
B  </ch>
</doc>

i.e.  both the nesting "level" and "order" are in the id attribute.

any tips appreciated.

B Dave.