rEGISTRACNI FORMULAR NA VLASTNOM WEBE

CREATE TABLE users
(
id int auto_increment not null primary key,
nick varchar(100) not null,
password varchar(200) not null,
name varchar(100) not null,
surname varchar(100) not null,
email varchar(100) not null,
ip varchar(100) not null,
reg_date varchar(100) not null
);

<?php

mysql_connect('localhost', 'root', '') or die ('Mysql error');
mysql_select_db('stranka') or die ('Mysql error');

$nick=trim(htmlspecialchars(addslashes($_POST['nick'])));
$password=sha1(addslashes($_POST['password']));
$password_confirm=md5(addslashes($_POST['password_confirm']));
$name=trim(htmlspecialchars(addslashes($_POST['name'])));
$surname=trim(htmlspecialchars(addslashes($_POST['surname'])));
$email=trim(htmlspecialchars(addslashes($_POST['email'])));
$time=date('d.m.Y g:i a');
$ip=$_SERVER['REMOTE_ADDR'];
if (!$ip){
    $ip='UNKNOWN';
    }

$sql='SELECT * FROM users WHERE nick="'.$nick.'"';
$result=mysql_query($sql);

if (mysql_num_rows($result)!=0){
 $error=1;
}
else{
 $error=0;
}

 if (isset($_POST['sent']))
 {
  if ($nick=='' || $password=='' || $password_confirm=='' || $name=='' || $surname=='' || $email=='')
  {
    print 'You must insert all information about you!';
  }
 else
 {
   if ($error==0)
    {
     if ($password == $password_confirm)
      {
      if (ereg('^.+@.+\\..+$', $email))
       {
      $sql='INSERT INTO users (`nick`, `password`, `name`, `surname`, `email`, `ip`, `reg_date`) VALUES ("'.$nick.'", "'.$password.'", "'.$name.'", "'.$surname.'",      "'.$email.'", "'.$ip.'", "'.$time.'")';
      $result=mysql_query($sql);
      header('Location: index.php?register=successful');
       }
     else
      {
        print 'Email is not valid';
      }
    }
     else {
             print 'Passwords are different';
           }
        }
   elseif ($error==1)
     {
       print 'This nick is already register';
     }
   }
 }

else {
    print 'Please insert all informations about you';
}



mysql_close();
?>
<center>
<form method="post">
Nick: <input type="text" name="nick" value="" size="20"><br>
Password: <input type="password" name="password" value="" size="20"><br>
Confirm password: <input type="password" name="password_confirm" value="" size="20"><br>
Name: <input type="text" name="name" value="" size="20"><br>
Surname:<input type="text" name="surname" value="" size="20"><br>
E - mail: <input type="text" name="email" value="" size="20"><br>
<input type="reset" value="Reset">
<input type="submit" name="sent" value="Register">
</form>