Upload file assignment submission problem

Hi there,

I found two problem in assignment submission.
A.) There is an "draft" entry (without any document shown, please refer to assignment_01.bmp) in the "View submitted Assignment" page if a student upload their assignment without press the Save Change button.
Steps:
1.) Login as teacher and add an online assignment.
2.) Login as student and go the assignment page
3.) Upload a file to the system (without pressing the Save Changes button).
4.) Click on any pages other than the current assignment page.
4.) Click the assignment title again and the student will get the message "No files submitted yet". The student can't find the submitted assignment.
4.) Login as teacher. The teacher will note that a student uploaded his assignment but you can access it.

Personally, I will suggest that system should automatically save the file in server once the student has uploaded the file to server.

B.) There is an entry (please refer to assignment_02.bmp) in the "View submitted Assignment" page if a student press Save Changes button without uploading any files
Steps:
1.) Login as a student and go the assignment page.
2.) Press the Save Changes button without uploading any files to the system
3.) Login as a teacher and check the assignment submission records. Then, I found that the system will mark the submitted as succesfully. But, of course, I can't access to any files.

It is a bug. I suggest that there should have a checking in the upload.php to disallow the student to press the Save Changes button if they haven't uploaded any files yet.

Thanks.