JavaScript/Working with files

With pure HTML4 and pure JavaScript, there's really only one thing you can do with the users files: The server sends a Web page that includes a form something like this:RFC 1867, RFC 2388 <form action="/upload_handler" method="post"> <input type="file" /> </form> and then, the browser allows the user to select one file, and the browser uploads it -- without any JavaScript on the client being able to see any of that data or cancel the transmission or even show a progress bar. If you want JavaScript to know anything about the file before it is transmitted (for example, to immediately cancel the transmission of a large file rather than wait an hour for the file to be transmitted, then tell the user "File too large"; or to show a progress bar), you'll have to use something other than pure JavaScript on pure HTML4. Some popular options are:Getting upload file size before uploadIs it possible to use Ajax to do file upload?File API: W3C Last Call Working Draft 12 September 2013Reading files in JavaScript using the File APIs use a modern Web browser that supports the HTML5 File API. use Flash (perhaps a tiny flash utility like Gmail uses to draw a little progress bar) use a Java applet use an ActiveX control References