SVG script

I have one problem with SVG script.
What I am trying to do is writing data into a file from SVG script.
The same javascript code for the file write is working fine when it is used within HTML file but not in SVG.

If I try to run this code from SVG browser, it gives me an error of:  'ActiveXObject' is undefined

Does anybody know why this is happening?

My javascript code looks like following:

  var fso = new ActiveXObject("Scripting.FileSystemObject");
  var MyFile = fso.CreateTextFile("test.dat", 8,true);
 
  MyFile.Write("....");
  MyFile.Close();

Thans in advance.