In IE 8, the sequence is "Tools -> Internet Options -> Privacy -> Settings ". Now enter bb.utsa.edu and click Add.
In Firefox, the sequence is: "Tools -> Options -> Content -> Exceptions (opposite Block Popup Windows)". Now enter bb.utsa.edu and click Allow.
After you have successfully added an attachment, you still need to click on "Submit" on the bottom of the page below "Add Attachments".
A successful submission will appear in your Submitted tab.
If you want to submit a new and improved version of your program, click on the icon to the right of the assignment (ActionLinks) and then select Take Submission Back to Inbox. Uploading a new zip file with the same name will overwrite the old zip file. Be sure to click Submit and to check the Submitted tab.