Using OptionButton

Hello all!

I want to use OpionBotton so that the user chooses one of two script execution options: 1. Uploading data to a file; 2. Download data from the file;

But I can not return the result after selecting one of the options. Help me please. This is my code: function getDialog1(){

   var flag = null;

   var dialog_templte = Dialogs.createNewDialogTemplate(0,0,400,200,"Settings");

   dialog_templte.OptionGroup("Choose");

   dialog_templte.OptionButton(15,25,390,15,"Uploading data to a file","V");

   dialog_templte.OptionButton(15,40,390,15,"Download data from the file", "Z");

   dialog_templte.OKButton();

   var myDialog1 = Dialogs.createUserDialog(dialog_templte);

   Dialogs.show(myDialog1);    this.getResult = function()

    {

      if(this.dialog.getPage(0).getDialogElement("V").isEnabled()){           

         flag = 0;

         Dialogs.MsgBox("Uploading: flag = 0");    // Did not appear

      }

      if(this.dialog.getPage(0).getDialogElement("Z").isEnabled()){           

         flag = 1;

         Dialogs.MsgBox("Downloading: flag = 1");  // Did not appear

      }

      Dialogs.MsgBox("Result: flag = " + flag);   // Did not appear

      return flag;

    }

   Dialogs.MsgBox("Result2: flag = " + flag);   // Appeared "Result2: flag = null"

   return flag;

}