are you using a multipart request? If not, or it doesn't ring a bell, then your upload will not work and won't get to the server. You should check our FAQ entry on FileUpload
Download the I/O library (commons-io-1.2.jar) from Apache Commons project and stick into the lib directory. That will resolved the NoClassDefFoundError exception.
File upload handles in a different manner. If you want to retrieve the standrd form items such as text fields you have to access them using the isFormField method of FileItem class.