Error 403 means 'Forbidden'. The W3C says this about a 403 error: "403 Forbidden.
The server understood the request, but is refusing to fulfill it..."
Contact your server admin or helpdesk and tell them you are using a java applet that is attempting to upload image files to a php script on your server and the server is returning a 403 Forbidden response.
Many server hosts allow you to view the server access logs which keep a record of every request to the server (so they are quite long). If you can locate the server log entry for the time the error occurred then it should give more information which may be useful when you contact the server admin.
The logs are usually stored in a 'logs' directory or similar and can be accessed by ftp. The entries are time-stamped so it is not too difficult to locate the entry for the 403 error. It's best to try an upload so it triggers the error and then find the entry in the log.
SimpleViewer Support Team.