Untitled

<?php
    $con = mysql_connect("localhost","root","wow");
    if (!$con)
    {
        die('Could not connect: ' . mysql_error());
    }

    mysql_select_db("login", $con) or die (mysql_error ());

    if(isset($_GET['action']))
    {
        switch($_GET['action'])
        {
        case 'checklogin':
        $loginusername=$_POST['account'];
        $loginpassword=$_POST['password'];

        $loginusername = stripslashes($loginusername);
        $loginpassword = stripslashes($loginpassword);
        $loginusername = mysql_real_escape_string($loginusername);
        $loginpassword = mysql_real_escape_string($loginpassword);

        $sql="SELECT * FROM accounts WHERE account='$loginusername' and password='$loginpassword'";
        $result=mysql_query($sql);

        $count=mysql_num_rows($result);

        if($count==1){
        session_register("loginusername");
        session_register("loginpassword");
        header("location:?action=loginsuccess");
        }
        else {
        session_start();
        $_SESSION['login'] = '';
        echo 'Wrong Username and or Password, please try again.<br><br><br><br><br>Click <a href="main.php">here</a> to go back to the login page.';
        }

        break;
        case 'loginsuccess':
        session_start();
        $_SESSION['login'] = "1";
        }
        echo "You have been logged in.<br><br><br><br><br>Click <a href=\"main.php\">here</a> to go back to the main page.";
        break;
        }
    }
    else
    {
        echo "<html>
        <body>

        <form action=\"?action=checklogin\" method=\"post\">
        Account:      <input type=\"text\" name=\"account\" /><br><br>
        Password:   <input type=\"password\" name=\"password\" /><br><br>
        <input type=\"submit\" value=\"Login\" />
        </form>

        </body>
        </html>";
    }