Remember:
If you want to perform multiple actions with a new node, you may need to create a copy of it before
means:
## Create an address to an unique memory block !
$td = $dom->createElement('td');
## Change some things in this original unique pattern
$td->setAttribute('class', 'saldo');
## clone the unique pattern to two own one's
$td1 = clone $td;
$td2 = clone $td;
## alter properties in each one
$td1->nodeValue = 'Ich bin die erste neue Node';
$td2->nodeValue = 'Ich bin die zweite neue Node';
## find the parent element
$tr = $dom->getElementById('t001-tr001');
## find the first and the last child (here only for clearity)
$first = $tr->firstChild;
$last = $tr->lastChild;
## produce the new nodes
$newtd1 = $tr->insertBefore($td1, $first);
$newtd2 = $tr->appendChild($td2);
conclusion:
YOU NEED AN ORIGINAL NEW NODE FOR EACH ACTION!