#!/usr/bin/perl

use XML::LibXML;

$parser = XML::LibXML->new();
$doc    = $parser->parse_file('student.xml');

$query  = '//student';

for my $ele ($doc->findnodes($query)){
	my $attr_text=$ele->getAttribute('id');
	if($attr_text eq '1001'){
		$new_ele=$doc->createElement('student');
		$new_ele->setAttribute('id','1003');
		$doc->insertAfter($new_ele,$ele);

		last;
	}
		
}

open(TESTFILE,">result.xml");
print TESTFILE $doc->toString;
close(TESTFILE);