Moving Ball in C

# include <graphics.h>
# include <stdlib.h>
# include <conio.h>
# include <dos.h>

int x,y,maxx,maxy,i,j;

int main(void)
{
int gdriver = DETECT, gmode;
void *image;
unsigned int size;
char ch;
void fillBox(int,int);
int Row,Col;

// Initialize graphics drivers and mode.
initgraph(&gdriver,&gmode,"d:\tc\bgi ");

// Draw a rectangle
// rectangle(x1,y1,x2,y2)
maxx=getmaxx(); // x2
maxy=getmaxy(); // y2
rectangle(10,10,maxx-10,maxy-10);

// Puts Pixel in the Rectangle.
fillBox(maxx,maxy);
x=y=70;
// Draw Circle and FillColor
setfillstyle(1,14);
circle(x,y,20);
floodfill(x,y,15);

// Creating the Image
size = imagesize(x,y,x+20,y+20);
image=malloc(size);
getimage(x-20,y-20,x+20,y+20,image);
x-=20;
y-=20;
// Will Displays till Any key is hit !!!...
while(!kbhit())
{
Row = x; Col = y;
putimage(x,y,image,XOR_PUT);    // clears the Image from Screen
//x=random(maxx-70);
//y=random(maxy-70);
//fillBox(maxx,maxy);
x=x+10;
  /* if(x<50)
x=50;
if(y<50)
y=50;*/
putimage(x,y,image,OR_PUT); // Puts the image on screen.
delay(50); // Waits for few Seconds.
if(x>540)
{
putimage(x,y,image,XOR_PUT);
Row = x; Col = y;
for(i=0;i<540;i++)
{
x=random(maxx-10);
y=random(maxy-10);
if(x>10 && y>10)
putpixel(x,y,14);
}
//putpixel(x,y,14);
x= Row;
y=Col;
x=10;
y=y+20;
putimage(x,y,image,XOR_PUT);
}
if(y>410)
{
putimage(x,y,image,XOR_PUT);
Row = x; Col = y;
fillBox(maxx,maxy);
x= Row;
y=Col;
x=10;
y=30;
putimage(x,y,image,XOR_PUT);
}
}
free(image); //Removes the image from the Screen.
closegraph(); // Closes the Graphics Mode.
}

void fillBox(int maxx,int maxy)
{
cleardevice();   // Clears the Graphics Screen
maxx=getmaxx(); // x2
maxy=getmaxy(); // y2
rectangle(10,10,maxx-10,maxy-10);
for(i=0;i<8000;i++)
{
x=random(maxx-10);
y=random(maxy-10);
if(x>10 && y>10)
putpixel(x,y,14);
}
}