If you are working with Xwin32 and linux, which I recommend, here is a way to submit your work:

• You can launch a web browser from Linux when you use Xwin 32. type firefox in the command prompt of a terminal.
• log on to your webCT account, and access the class page (do not pay attention to the missing plug in, it is not important).
• On the course tools, go to assignments and click on Lab n.
• To submit your files, submit them as attachments (click on add attachment, my computer, and browse to select your files).
• you can add comments if you feel like.
• Do not forget to click on the submit button! Once you click on the submit button, you should have an aknowledgment page, with a yellow frame saying:
  Your name
  You have successfully submitted your assignment(Lab n).
  Submitted Time: August 24, 2006 10:43 AM
  

Also, it is possible to re-submit. To do that, go to Assignments in the menu on the left, and then go to the Submitted tab (located on the top of the page), and click on Lab n. click on the following icon located on the right of the following text: Submitted on August 24, 2006 10:43 AM (Attempt #1). To re-submit the same file, click on add attachment and select the file again. WebCT will ask a confirmation to overwrite the file. Again, do not forget to click on the submit button.