public void setStateThreeFieldsEntered( String digit )
    {
        this.numCount = 3 ;
        notifyObservers() ;
         //if(this.numCount == 3)
            System.out.println("thank you");
        this.state = field3 ;
        if ( digit != null )
        {
         if(this.validPin(digit)){

            this.str3 = digit ;
                    debug() ;
        }
            else{
                this.invalidPin();
                        debug() ;
            }
        }

           else{
                this.state.invalidPin();
            }

            System.out.println( "Authenticating..." ) ;
            this.pin.validate( str1+str2+str3) ;
            if ( !this.pin.isAuthenticated() )
                  setStateNoFieldEntered() ;
        }