ExtendScript doesn't recognize variables passed to doc.NewAnchoredFormattedVar (b_var, textLoc) !

Hi all,

I am currently developing a script that automates the addition of new paragraph text comprising variables and string. b_user_inputis the the variable name defined in framemaker which is input by the user. However doc.NewAnchoredFormattedVar is not able to recognize the same and prints nothing in the document. Then I tried putting the input string within quotes thinking it might work, but that didn't work too(i.e.  var  b_var = "\""+ffFmt.Name+"\"";

          var bbFmt = doc.GetNamedObject (Constants.FO_VarFmt, b_user_input);   //b_user_input = "Variable_b"

          var  b_var =bbFmt.Name;

          doc.AddText (textLoc, "Var_b value: ");

          doc.NewAnchoredFormattedVar (b_var, textLoc);      //       doc.NewAnchoredFormattedVar ("Variable_b", textLoc);  This method works.

It would be great if you could let me know how to make this work.      

Thanks,

Sebin