mouse callback in visual stdio

#include <GL/glut.h>
#include<stdio.h>
#include<iostream>
  int ww=600,wh=400;
  int first=0;

  void drawLine()
  {

  }


  void display()
 {     glClearColor(0.0,0.0,0.0,1.0);
       glClear(GL_COLOR_BUFFER_BIT);
       glFlush();
 }


  void mouse(int btn,int state,int x,int y)
  {
      if(btn == GLUT_LEFT_BUTTON && state == GLUT_DOWN)
      {
      exit(1);
      }

      if(btn == GLUT_RIGHT_BUTTON && state == GLUT_DOWN)
      {
      printf("%d %d\n",x,y);
      glBegin(GL_POINTS);
      glVertex2f(x,wh-y);
      glEnd();
      glFlush();
      }
  }

  void reshape()
  {
       glViewport(0,0,ww,wh);
       glMatrixMode(GL_PROJECTION);
       glLoadIdentity();
       gluOrtho2D(0.0,(GLdouble)ww,0.0,(GLdouble)wh);
       glMatrixMode(GL_MODELVIEW);
  }


  int main(int argc,char** argv)
  {
       glutInit(&argc,argv);
       glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
       glutInitWindowSize(ww,wh);
       glutCreateWindow("Draw Line With Mouse Click");
       glutDisplayFunc(display);
       reshape();
      glutMouseFunc(mouse);
       glutMainLoop();
       return 0;
  }