opencv关于视频中画矩形的有关问题？求高手

opencv关于视频中画矩形的问题？？？求高手
我的程序是这样的 坐标能显示出来，就是画不出矩形
#include "stdafx.h"
#include <stdio.h>
#include <cv.h>
#include <cxcore.h>
#include<stdlib.h>
#include"highgui.h"

 CvRect box;
 bool Drawing=false;
 
 void MouseDraw(int event,int x,int y,int flags,void*param);
 
void DrawRect(IplImage*pFrame,CvRect rect)
 {
  cvRectangle(pFrame,
  cvPoint(box.x,box.y),
  cvPoint(box.x+box.width,box.y+box.height),
  cvScalar(0xff,0x00,0x00));
 }
int main(int argc,char **argv)
  {
box=cvRect(0,0,-1,-1);
IplImage* pFrame = NULL; 
  IplImage* pFrImg = NULL;
  IplImage* pBkImg = NULL;

  CvMat* pFrameMat = NULL;
  CvMat* pFrMat = NULL;
  CvMat* pBkMat = NULL;

int nFrmNum=0;

  cvNamedWindow("video",CV_WINDOW_AUTOSIZE);
  cvNamedWindow("background",1);
  cvNamedWindow("foreground",1);

  cvMoveWindow("video", 30, 0);
  cvMoveWindow("background", 360, 0);
  cvMoveWindow("foreground", 690, 0);

CvCapture *pCapture=cvCreateFileCapture("tingche.avi");

  while(pFrame = cvQueryFrame( pCapture ))
  {

  nFrmNum++;
printf("第%d帧\n",nFrmNum);
cvSetMouseCallback("video",MouseDraw,(void*)pFrame); //Set the callback function of mouse event
  IplImage*temp=cvCloneImage(pFrame);
  cvCopyImage(pFrame,temp);
  if(Drawing)
  DrawRect(temp,box);
  cvShowImage("video",temp);
  //如果是第一帧，需要申请内存，并初始化
  if(nFrmNum == 1)
{
pBkImg = cvCreateImage(cvSize(pFrame->width, pFrame->height), IPL_DEPTH_8U,1);
pFrImg = cvCreateImage(cvSize(pFrame->width, pFrame->height), IPL_DEPTH_8U,1);

pBkMat = cvCreateMat(pFrame->height, pFrame->width, CV_32FC1);
pFrMat = cvCreateMat(pFrame->height, pFrame->width, CV_32FC1);
pFrameMat = cvCreateMat(pFrame->height, pFrame->width, CV_32FC1);

//转化成单通道图像再处理
cvCvtColor(pFrame, pBkImg, CV_BGR2GRAY);
cvCvtColor(pFrame, pFrImg, CV_BGR2GRAY);

cvConvert(pFrImg, pFrameMat);
cvConvert(pFrImg, pFrMat);
cvConvert(pFrImg, pBkMat);
}
  else
{
cvCvtColor(pFrame, pFrImg, CV_BGR2GRAY);
cvConvert(pFrImg, pFrameMat);
//高斯滤波先，以平滑图像
//cvSmooth(pFrameMat, pFrameMat, CV_GAUSSIAN, 3, 0, 0);
 
//当前帧跟背景图相减
cvAbsDiff(pFrameMat, pBkMat, pFrMat);

//二值化前景图
cvThreshold(pFrMat, pFrImg, 60, 255.0, CV_THRESH_BINARY);

//进行形态学滤波，去掉噪音  
//cvErode(pFrImg, pFrImg, 0, 1);
//cvDilate(pFrImg, pFrImg, 0, 1);

//更新背景
cvRunningAvg(pFrameMat, pBkMat, 0.003, 0);
//将背景转化为图像格式，用以显示
cvConvert(pBkMat, pBkImg);

//显示图像
cvShowImage("video", pFrame);
cvShowImage("background", pBkImg);
cvShowImage("foreground", pFrImg);

//如果有按键事件，则跳出循环
//此等待也为cvShowImage函数提供时间完成显示
//等待时间可以根据CPU速度调整
char c=cvWaitKey(33);
 
}

  }

   


  //销毁窗口
  cvDestroyWindow("video");
  cvDestroyWindow("background");
  cvDestroyWindow("foreground");

  //释放图像和矩阵
  cvReleaseImage(&pFrImg);
  cvReleaseImage(&pBkImg);

  cvReleaseMat(&pFrameMat);
  cvReleaseMat(&pFrMat);