This is a demonstration of using 'ajas.http.uploadLocalFile' to upload a file without a pageload (ie, via 'AJAX'). Because of Browser security that prevents reading the file from the local computer it only works in FireFox, and requires a special setting change in about:config. Once the file is read, it calls 'ajas.http.uploadAsFile' with the contents, which should work in any browser. The size of the file should extend to the limit of the server's configuration, however I have set a small limit for demonstrative purposes.
FireFox/Mozilla settings: Open about:config and check that [signed.applets.codebase_principal_support] is set to "true"