Deal with missing tags in XML file

Hey guys, I need to read information from a xml file. However, in this file, for some nodes, it contains more subchildnodes than other nodes, here's the file:

<?xml version="1.0" encoding="utf-8"?>
<Green>
<ROWSET>
 <ROW>
   <A>text goes here</A>
   <B>text goes here</B>
   <C>text goes here</C>
 </ROW>
 <ROW>
   <A>text goes here</A>
   <B>text goes here</B>
 </ROW>
 <ROW>
   <A>text goes here</A>
   <B>text goes here</B>
   <C>text goes here</C>
 </ROW>
</ROWSET>
</Green>

Note that the 1st&3rd "ROW" has tag <C></C> while the 2nd doesn't. So I use Xpath and successfully recognize the missing tag in the 2nd <ROW> tag. Here's my code:

var row1 = xmlDoc.evaluate("/GreenSpot/ROWSET/ROW["+1+"]/C/text()")?"row1 exist!":"row1 NOT exist!";
var row2 = xmlDoc.evaluate("/GreenSpot/ROWSET/ROW["+2+"]/C/text()")?"row2 exist!":"row2 NOT exist!";
var row3 = xmlDoc.evaluate("/GreenSpot/ROWSET/ROW["+3+"]/C/text()")?"row3 exist!":"row3 NOT exist!";

So I get "row1 exist! row2 NOT exist! row3 exist!". This works for iPhone. When I put the same code on Android, it says "row2 exist!". I have also try

xmlDoc.documentElement.getElementsByTagName("TEST").item(n)

When n=3, it throws nullPointerError. But what I want is when n=2, I can know the 2nd doesn't have <C></C>.
Is there any way to do this on android?