Implementation of MOUSE EVENT in c language

#include<stdio.h>
#include<graphics.h>
#include<dos.h>

union REGS i,o;

void restrictmouseptr(int x1,int y1,int x2,int y2)
{
    i.x.ax=7;
    i.x.cx=x1;
    i.x.dx=x2;
    int86(0x33,&i,&o);
    i.x.ax=8;
    i.x.cx=y1;
    i.x.dx=y2;
    int86(0x33,&i,&o);
}

void getmousepos(int *button,int *x,int *y)
{
    i.x.ax=3;
    int86(0x33,&i,&o);
    *button=o.x.bx;
    *x=o.x.cx;
    *y=o.x.dx;
}


void main()
 {
    int gd=DETECT,gm,x,y,maxx=630,maxy=451,button;
    initgraph(&gd,&gm,"c:\\tc\\bgi");
    rectangle(0,90,maxx,maxy);
    setviewport(1,91,maxx-1,maxy-1,1);
    gotoxy(33,1);
    printf("Mouse Events");
    i.x.ax=0;
    int86(0x33,&i,&o);
    if(o.x.ax==0)
     {
    restorecrtmode();
    printf("Mouse Driver is not loaded.");
     }
    restrictmouseptr(1,91,maxx,maxy-1);
    i.x.ax=1;
    int86(0x33,&i,&o);
    gotoxy(1,3);
    printf("Left Button ");
    gotoxy(25,3);
    printf("Rigth Button ");
    gotoxy(50,5);
    printf("press any key to exit.........");
      while(!kbhit())
      {
    getmousepos(&button,&x,&y);
    gotoxy(1,5);
    if((button&1)==1)
    printf("Key is Pressed  ");
    else
    printf("Key is Released  ");
    gotoxy(25,5);
    if ((button&2)==2)
    printf("Key is Pressed  ");
    else
    printf("Key is Released  ");
    gotoxy(65,3);
    printf("x= %d  y= %d ",x,y);
      }
  }