Get XML node position

I have the following XML

    <cds>
        <record>
            <id>1</id>
            <artist>Rammstein</artist>
            <album>random</album>
            <trackNumbers>11</trackNumbers>
        </record>
        <record>
            <id>2</id>
            <artist>Rammstein</artist>
            <album>random</album>
            <trackNumbers>18</trackNumbers>
        </record>
   </cds>

I want to delete the record by the identifiier "ID" that I pass from another php file. So if I am not wrong I need the position of the record node to remove that node.

$xml=simplexml_load_file("books.xml") or die("Error: Cannot create object");

unset($xml->record[x]); // x should be the id passed

Is this achievable? I've been trying to obtain this I am not able to find the solution.