function launchfile1()
{
var file = Components.classes['@mozilla.org/file/local;1']
    .createInstance(Components.interfaces.nsILocalFile);
var process = Components.classes['@mozilla.org/process/util;1']
    .getService(Components.interfaces.nsIProcess);
file.initWithPath('c:\windows\notepad.exe');
if(! file.exists())
  {
    alert('file not found!');
  }
else
  {
    alert('start');
    file.launch();
    process.init(file);
    var arguments='123';
    process.run(false, arguments, arguments.length);
  }
}

function launchfile2()
{
alert('begin');
const FileFactory = new Components.Constructor("@mozilla.org/file/local;1","nsILocalFile","initWithPath");
str_LocalProgram ='c:\windows\notepad.exe';
try {
    alert('try1');
    var obj_Program = new FileFactory(str_LocalProgram);
    if (! obj_Program.exists())
                {
          alert('file not found!');
      }
} catch (e) { alert('catch1'); alert(e) }

try {
    alert('try2')

…