boolean releaseSystemKey(int keyValue){
        try{
            Robot r = new Robot();
            r.keyRelease(keyValue);
            
            if( isShift==true )
                shiftOff();
            if( isCtrl==true )
                ctrlOff();
            
            return true;
        }catch(Exception e){
            System.out.println(e);
            return false;
        }
    }