drwing horizontal & Verticle line on the screen

/* using graphics */
#include
#include
#include
main()
{
int gd=DETECT,gm,midx,midy;
int i=1;
initgraph(&gd,&gm,"d:\\cpp\\bgi");
midx=getmaxx()/2;
midy=getmaxy()/2;
/* drwing horizontal line on the screen */
line(1,480/2,640,480/2);

/* drwing vertical line on the screen */
line(320,1,320,480);

/* drwing circle */
circle(midx,midy,10);
getch();

}