Thanks, but that's not really what I need.
My chart should count in the first coulumn the clicks on the fisrt newsletter a contact has received. In the second, the second and so forth.
So in the example the first coulumn will count the clicks, if any, at idContact=1 and idNewsletter=1, idContact=2 and idNewsletter=2 (because the newsletter 2 is the first for contact 2), idContact=3 and idNewsletter=3 ... Then in the second column it count the clicks, if any, at idContact=1 and idNewsletter=2, idContact=2 and idNewsletter=3, idContact=3 and idNewsletter=4... The second newsletter received by each contact. And so forth .
Is it any clearer?
Thanks a lot!