uploading files problem

hi there, I'm trying to upload a file using php on an apache server running on linux. The code of the form I'm using is as follow: <form enctype=\"multipart/form-data\" method=POST action=$PHP_SELF?action=doupload > <p>File to upload:<br> <input type=file name=file size=30> <input type=text name=zio size=30> <p><button name=submit type=submit> Upload </button> </form> when I press the submit button after selecting the file, nothing happens. I tried to print the filename passed by the form but it is empty. If I run the same page on my win2k server, everything works fine. It seems as that the form doesn't pass post variables. I also tried to delete the enctype parameter and in this case the variables are printed on screen. Is there any particular setting on linux for this page to work? thanks