It was a good solution!
Though, I used a global variable $id passed any time to $PHP_SELF for moving to the various properties in the db because it doesn't work otherwise.
Still I have the following problem:
While moving from one link to another, so passing various values for $id, if I press the Refresh button of the browser it redirects me not to the initial page but to the page with the last $id passed.
What can I do?