Many thanks Scott,Your example worked also for me and directed me to the origin of the problem.The problem was originated by the calling page, where the sample page was called by:window.open('','TestServer',"menubar=yes,scrollbars=yes,status=yes,resizable=yes,toolbar=yes,width=800, height=600);
With this function I.E. doesn't show the referrer page and, I don't know why, Firefox does show the referrer page, i'll do some other tests to try to discover the motivation.Many thanks also to other people for the receiveed help,Michele