Line using Bresenham's method

#include"stdio.h"
#include"conio.h"
#include"graphics.h"
#include"math.h"
void main()
{
int i =DETECT,M,j;
int x1,y1,x2,y2,dx,dy,inc1,inc2,x,y,d,xend;
clrscr();
initgraph(&i,&M,"");
printf("Enter the values of x1,y1,x2,y2");
scanf("%d%d%d%d",&x1,&y1,&x2,&y2);
dx=(x2-x1);
dy=(y2-y1);
inc1=2*(dy-dx);
inc2=2*dy;
d=inc2-dx;
if(dx<0)
{
x=x2;
y=y2;
xend=x1;
}
else if(dx>0)
{
x=x1;
y=y1;
xend=x2;
}
while(x<=xend)
{
x++;

if(d<0)
{
d=d+inc1;
}
else if(d>=0)
{
d=d+inc2;
y=y+1;
}
putpixel(x,y,1);
} getch();
}