button to Print page or Click actions on list to Print page

Hi,

i'd like to insert a button in list page or edit page that redirect to print page of my record.
i put in the on Client after

location.href="distinte_print.php";
but the page opened is always the print page of my 1st record in the table "distinte"
the same if i use click actions - open page - Print Page on a field of my list page of table "distinte".
how may i pass the key value of the record to the print page?
phprunner enterprise 9.8 build 29929 x64
thanks

Fabio