help! linux 7 problems

hi, i installed php4 onto my linux 7.0 system along with apache and mysql. the apache and mysql work. once i did 'make install' for php, i changed the http.conf file in apache so that the AddType lines were uncommented out and the file extensions should be recongized. i've done this on windows and it worked. now, however, when i try to path to a .php file like localhost/test.php, it tries to save the file to disk instead of executing the code. anybody know why? thanks, rg