private void Form1_Paint(object sender, PaintEventArgs e)
{
    // حالت معمولی
    e.Graphics.DrawEllipse(new Pen(Color.Red, 10), 30, 30, 50, 50);

    //  SmoothingMode.AntiAlias  روانسازی به کمک
    e.Graphics.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias;
    e.Graphics.DrawEllipse(new Pen(Color.Blue, 10), 30, 100, 50, 50);
}
          

            
<?php
//retrieve form variables
$isbn = $_POST['isbn'];
$author = $_POST['author'];
$title = $_POST['title'];
$price = $_POST['price'];
$page = $_POST['page'];
if (strlen($isbn) == 0 or strlen($author) == 0)
{ 
   echo "Go  back and fill all fields !";
   exit;
}
//connet to MySQL server
$db = mysql_connect();
if(!$db)
{
     echo " Error : cannot open connection.";
     exit;
}
mysql_select_db('publisher');
$query = " insert into books 
                (isbn, author, title, price, page) values
                ('".$isbn."', '". $author."', '".$title."' ,'".$price."' ,  '".$page."' )";
$result = mysql_query($query);
if($result)
   echo mysql_affected_rows(). '<b> book inserted into database.</b>';
mysql_close($db);
?>