note space_monk Not really. Even if the code uses both arrays then there is nothing preventing building a temporary hash through <code> my %hash = map { $_ => 1 } @first_list; </code> ..and then discarding the hash after the check for new machines. More likely is that he is only interested in the second list, or just new machines, and they could be in an array just like before. <!-- Node text goes above. Div tags should contain sig only --> <div class="pmsig"><div class="pmsig-880879"> A Monk aims to give answers to those who have none, and to learn from those who know more. </div></div> 1003945 1003985