Simple Frame code issue

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int main()
{
    VideoCapture vid(0);
    if(!vid.isOpened())
        return 1;
    double rate= vid.get(CV_CAP_PROP_FPS);
    Mat frame,temp;
    namedWindow("temp");
    int delay=2000;
    bool stop(false);
    vid>>temp;
    while(!stop)
    {


        vid>>frame;

    imshow("temp",temp);


        if(waitKey(delay)>=0)
            stop=true;

    }
    imshow("Frame",frame);
    imshow("Ex Frame",temp);
    Mat dif=(temp - .5 * frame);
    imshow("x frame",dif);
    vid.release();



    waitKey();

    return 0;
}

In the above code the 'temp' is acquired before the loop and is shown in the loop and i expected to get only the first frame as output but i get the continuous frame output i just cant figure it out its just as if i've written "imshow("temp",frame);" Please help..silly thing...big headache...