tdom - not understanding "nextSibling"

[chedderslam]

I have a simple xml document:
<recordset>
 <division name="myname">
  <coe_division_name>MISSISSIPPI VALLEY</coe_division_name>
  <division_abbreviation>MVD</division_abbreviation>
 </division>
</recordset>

Whe I am parsing it and get to the node:
<coe_division_name>MISSISSIPPI VALLEY</coe_division_name>
I am running this code:
set myvar [$doc nextSibling]
however, the result is blank.

What would constitute a sibling?  How can I check if there is another
element on the same level of nesting right after the current element?

Thank you.