note LanX Ehm ... what am I missing here? like IMHO just searching for a repeated digit like with <c>/(\d).*\1/</c> and inverting the result should do.<P> <c> DB<111> print $_ !~ /(\d).*\1/ ? "$_ ok\n" :"$_ has <$1>\n" for qw/012 0102 01233/ 012 ok 0102 has <0> 01233 has <3> </c> <!-- Node text goes above. Div tags should contain sig only --> <div class="pmsig"><div class="pmsig-708738"> <p>Cheers Rolf </div></div> 142950 142950