How to calculate total child of screen?

<?xml version=‘1.0’ encoding=‘UTF8’?>
<data>
<screen id="" title="">
<row>110011101</row>
<row>110011101</row>
<row>110011101</row>
<row>110011101</row>
<row>110011101</row>
</screen>
</data>

I tried following code, but it’s not working
var rows:XMLList = temp_xmldata.children();
trace(rows.length);