#include <stdio.h>
#include <conio.h>
#include <graphics.h>
main()
{
 int gd=DETECT;
 int gm=DETECT;
 int x1,y1,x2,y2,i,j,flag=0;
 detectgraph(&gm, &gd);
 initgraph(&gm,&gd,"c:\\turboc\\tc\\bgi");
 cleardevice();
 printf("\n Enter the x-coordinate for line 1 : ");
 scanf("%d",&x1);
 printf("\n Enter the y-coordinate for line 1 : ");
 scanf("%d",&y1);
 printf("\n Enter the x-coordinate for line 2 : ");
 scanf("%d",&x2);
 printf("\n Enter the y-coordinate for line 2 : ");
 scanf("%d",&y2);
 clrscr();
 for(i=y1;i<y2;i++)
 {
  putpixel(x1,y1,RED);
  y1++;
  x1++;
 }
 getch();
}