i don't what exactly you want. maybe thats a solution:
$new = array("a", "b", "c");
$old = array("aa", "bb", "cc");
reset($new); reset($old);
while ( (list(,$value1) = each($new)) && (list(,$value2) = each($old)) )
{
echo "FROM NEW:$value1<br>";
echo "FROM OLD:$value2<br>";
}