Is it possible to have JavaScript on a Mac (10.6.8) retrieve the computers User ID Name so I can plug that into this script & apply that to a different text box?

This is what I'm starting with & think may need just to change the one Regular expression line.

var textFrames = activeDocument.textFrames;
      for (var i = 0 ; i < textFrames.length; i++)
        if (textFrames[i].note == "UPPER FORDDOC NAME") {
          var frameName = textFrames[i].contents ;
          newFrame = frameName.replace (/(.*-.*-.*)-(.*)/, "$1$2") ;
So when I run it on my computer it will see my User ID Name which is BLAU then put that into the text box in Illustrator but if JOHN DOE ran it on his computer it would put JDOE (His User ID Name).