Yes I did now but not before I posted it for the second time. Just to make some things clearer. I want to compare the first $site from the first @site, with all the $sites from the second @site and then move to the second $site from the first @site with all the $sites from the second @array, until I run over the whole first @array. Another thing is that I want to cobine the corresponding letters that means if $site1= 'ABCD' and $site2 = 'EFGH', then I only want the combinations 1-1, 2-2, 3-3, 4-4, that is AE, BF, CG, DH. And finally one other thing. I want to reset the counters to 0 everytime that I move from the first $site of @array1 to the second $site of @array1. I hope that this makes sence. Once again thanks for all the answers and the help .