Untitled

ex. html
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />
<title>Untitled Document</title>
</head>

<body>
<p>&nbsp;</p>
<form action="loginform.php" method="post">
User Name:<input type="text" name="username" /><br /><p>
Password:<input type="password" name="password" /><br /><p>
<input type="submit" name="submit" value="Login" />
</form>
</body>
</html>


loginform.php
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />
<title>Untitled Document</title>
</head>

<body>
<?php
session_start();
$username=$_POST['username'];
$password=$_POST['password'];

if ($username&&$password)
{
$connect = mysql_connect("localhost","root"," ");
if(!$connect)
{ die("couldn't find database"); }
mysql_select_db("sample");
$query = mysql_query("select * from login where username='$username'");
$numrows = mysql_num_rows($query);

if($numrows!=0)
{
while($row = mysql_fetch_assoc($query))
{
$dbusername = $row['username'];
$dbpassword = $row['password'];

}
if($username==$dbusername&&$password==$dbpassword)
{
echo 'Login successful';
$_SESSION['username']= $dbusername;
}
else
echo 'Incorrect Password';
} //end of numows
else
die("That username doesnt exist");
} // end of first if
else
die("Please enter username and password");
mysql_close($connect);
?>
</body>
</html>