Get the file size from Client side JavaScript

This explains how to determine the file size of the client system file from JavaScript

The following code could be used to determine the file size from the javascript which is useful at the time of uploading where in you can check before server side processing, on the client side itself

   var fileObj = new ActiveXObject("Scripting.FileSystemObject");
   var fName = document.getElementById('file1');
   upLoadfile = fileObj.getFile(fName);
   fSize = upLoadfile.size;