To upload files using PHP or JSP, or in general to modify the contents of a sub-directory of the public_html directory in your login directory, you must grant permission to the user to write into that sub-directory. If that sub-directory is to be called "UPLOADS", then do this:
mkdir ~/public_html/UPLOADS
fs sa ~/public_html/UPLOADS http write
Then, in your PHP or JSP code, specify that files be uploaded to </full/path/to/UPLOADS>
Note: For web servers other than web.njit.edu, replace "http" with the Kerberos principal that the web server runs under - contact arcs@njit.edu for more information.