is it possible to read a file using javascript?

Firstly I think its not a good idea to read a file locally with JavaScript. I recommend first upload it to the server and then perform the reading.

Having said that it is possible, but you restricted by what you can do.

Im assuming its a local file on the user machine, otherwise AJAX would achieve this for a server read.

It might be possible through

1. Windows Script Host Object Model(WScript.Shell) and when granted Prompt or Enable access to ActiveX the browser has elevated privileges (Enable through Tools > Internet Options > Security > Custom Level ... > Set Active X settings to prompt). If this is still to difficult, user could download something thats installed and then does the reading through Shell Scripting! Disclaimer: Note I do not recommend this approach. Its not active for a reason and its so DIRTY (I feel dirty)!

2. Cookies might also be worth considering. If you can store the information in a cookie the JavaScript would be able to read, write and update it.

   Found this code from http://www.quirksmode.org/js/cookies.html scroll right to the bottom for the example.

   function createCookie(name,value,days) {
   if (days) {
       var date = new Date();
       date.setTime(date.getTime()+(days*24*60*60*1000));
       var expires = "; expires="+date.toGMTString();
   }
   else var expires = "";
   document.cookie = name+"="+value+expires+"; path=/";
   

   }

   function readCookie(name) {
       var nameEQ = name + "=";
       var ca = document.cookie.split(';');
       for(var i=0;i < ca.length;i++) {
           var c = ca[i];
           while (c.charAt(0)==' ') c = c.substring(1,c.length);
           if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length,c.length);
       }
       return null;
   }
   
   function eraseCookie(name) {
       createCookie(name,"",-1);
   }