Untitled

<?php
 require("connect.php");

$submit = $_POST['submit'];
$username = mysql_real_escape_string($_POST['username']);
$email = mysql_real_escape_string($_POST['email']);
$password = mysql_real_escape_string($_POST['password']);
$password_again = mysql_real_escape_string($_POST['password_again']);
$date = date("Y-m-d ");

if($submit){
  if($username && $email && $password && $password_again){

    if($password == $password_again){

      $complex = preg_match('/\d/',$password);
      $pass_len = strlen($password);
      if($complex && $pass_len >= 8){

        $password = crypt($password, '$2a$30$kj34/3JZ345F3fR6/hH21/$');

        $chk_username = mysql_query("SELECT username FROM users WHERE LOWER(username) = LOWER('$username')") or die("Error, checking username.");
        $num_rows = mysql_num_rows($chk_username);

        if($num_rows === 0){
          $set_reg = mysql_query("INSERT INTO users (username, password, email, date) VALUES('$username','$password','$email','$date')") or die("Error, inserting user");
          echo "Thank you for registering.";
        }else{
          echo "Sorry, the username <b>$username</b> is already taken.";
        }
      }else{
        echo "For security, you password my be at least</br> 8 characters long and contain numbers!";
      }


    }else{
      echo "Your passwords do not match";
    }
  }else{
    echo "Please fill in <b>ALL</b> fields.";
  }
}
?>

<!DOCTYPE HTML>
<html>

<head>
<meta http-equiv="Content-Type" content="text/html;charset=utf-8" >
<title>Register</title>
</head>

<body>
<form action='register.php' method = 'POST' >
  <table>
  <tr>
    <td>Username:</td>
    <td><input type='text' name='username' value='<?php echo $username;?>' /></td>
  </tr>
  <tr>
    <td>E-Mail:</td>
    <td><input type='text' name='email' value='<?php echo $email;?>' /></td>
  </tr>
  <tr>
   <td>Password:</td>
   <td><input type='password' name='password' /></td>
   </tr>
   <tr>
   <td>Password again:</td>
   <td><input type='password' name='password_again' /></td>

  </tr>
  </table><p>
  <input  type='submit' name='submit' value='Register' />

</form>
</body>
</html>