Given an XML file similar to the following:

<root>
    <child>
        <key1>1</key1>
        <key2>1</key2>
        <origkey1/>
        <origikey2/>
        <flag>0</flag>
    </child>
    <child>
        <key1>1</key1>
        <key2>2</key2>
        <origkey1>1</origkey1>
        <origikey2>1</origkey2>
        <flag>0</flag>
    </child>
    <child>
        <key1>2</key1>
        <key2>1</key2>
        <origkey1>1</origkey1>
        <origikey2>1</origkey2>
        <flag>0</flag>
    </child>
    <child>
        <key1>2</key1>
        <key2>2</key2>
        <origkey1>2</origkey1>
        <origikey2>1</origkey2>
        <flag>1</flag>
    </child>
</root>

I want to transform it into:

<root>
    <child>
        <key1>1</key1>
        <key2>1</key2>
        <origkey1/>
        <origikey2/>
        <flag>0</flag>
    </child>
    <child>
        <key1>1</key1>
        <key2>2</key2>
        <origkey1>1</origkey1>
        <origikey2>1</origkey2>
        <flag>0</flag>
    </child>
</root>

This is done due to the flag element having a value of 1 in the last record.
This indicates that the child with key1 = origkey1 and key2 = origkey2 is
not to be included in the result set.  The deletion indicator child can
appear either before or after the child that needs to be deleted.

Any ideas on how to go about doing this?

Thanks
Andy