How to save as AI file with PDF compatability at the same location?

Please test this on some none important directories of files. It would appear to work for me finding just the AI files to open and re-save. Wouldn't like to set something off trawling through folders n it not be right… Should you wish to override the app's dialogs then un-comment those lines you will not be warned about missing links and such alike… Also Change the value to 14 for CS4 compatibility where indicated…

#target illustrator

var df = new Folder('~/Desktop');

var topLevel = Folder.selectDialog('Please choose your Top Level Folder…', df).fsName;

var fileList = new Array();

fileListRecursive(topLevel, /\.ai$/i);

if (fileList.length > 0) {
     main();     
} else {
     alert('This Folder or sub folders contained NO Illustrator AI files?');     
}

function main() {
     with (app) {
          while (documents.length) {
                 activeDocument.close(SaveOptions.PROMPTTOSAVECHANGES);
            }
          //var orginalUIL = userInteractionLevel;     
          //userInteractionLevel = UserInteractionLevel.DONTDISPLAYALERTS;
          
          for (var a = 0; a < fileList.length; a++) {
               var docRef = open(fileList);
               with (docRef) {
                    var aiOptions = new IllustratorSaveOptions();
                    aiOptions.compatibility = Compatibility.ILLUSTRATOR12; // Change to 14 for CS4
                    aiOptions.pdfCompatible = true;          
                    aiFilePath = new File(fullName);
                    saveAs(aiFilePath, aiOptions);
                    close(SaveOptions.DONOTSAVECHANGES);
               }
          }          
          //userInteractionLevel = orginalUIL;
     }
}

function fileListRecursive(f, exp) {          
     var t = Folder(f).getFiles();
     for (var i = 0; i < t.length; i++) {
          if (t instanceof File && RegExp(exp).test(t.fsName)) fileList.push(t);
          if (t instanceof Folder) fileListRecursive(t.fsName, exp);
     }
}