PHP: If-Statement & Form -

my code ...

<?php         $username = mysql_real_escape_string($_post['username']);         $password = mysql_real_escape_string($_post['password']);         $passwordr = mysql_real_escape_string($_post['passwordr']);         $email = mysql_real_escape_string($_post['email']);          if(empty($username) || empty($password) || empty($passwordr) || empty($email)) {             echo '<div class="alert alert-danger">bitte fülle alle felder aus.</div>';         }          elseif(!preg_match('/^[a-za-z0-9-_^#]{4,15}$/', $username)) {             echo '<div class="alert alert-danger">bitte gebe einen gültigen usernamen ein.<br />der username muss mindestens 4 und maximal 15 zeichen lang sein und darf nur folgende sonderzeichen enthalten: -_^#</div>';         }          elseif(!preg_match('/^[a-za-z0-9-_*^#?!.,;@€]{8,20}$/', $password)) {             echo '<div class="alert alert-danger">bitte gebe ein gültiges passwort ein.<br />das passwort muss mindestens 8 und maximal 20 zeichen lang sein und darf nur folgende sonderzeichen enthalten: -_*^#?!.,;@€</div>';         }          elseif($passwordr != $password) {             echo '<div class="alert alert-danger">die passwörter stimmen nicht überein.</div>';         }          elseif(!preg_match('/^[a-za-z0-9-_.]+@[a-za-z0-9-_.]+\.[a-za-z]{2,4}$/', $email)) {             echo '<div class="alert alert-danger">bitte gebe eine gültige e-mail adresse ein.</div>';         }          else {             die("have n1 day");         }     ?> 

somehow, <div class="alert alert-danger">bitte fülle alle felder aus.</div>, when forms aren't empty.

why?

here's form ...

<div class="row">         <form method="post">             <fieldset>                 <div class="col-lg-5">                     <div id="username-group" class="form-group">                         <label for="username">username</label>                         <input type="text" name="username" id="username" class="form-control" placeholder="username">                     </div>                     <div id="password-group" class="form-group">                         <label for="password">passwort</label>                         <input type="password" name="password" id="password" class="form-control" placeholder="passwort">                     </div>                     <div id="passwordr-group" class="form-group">                         <label for="passwordr">passwort wiederholen</label>                         <input type="password" name="passwordr" id="passwordr" class="form-control" placeholder="passwort wiederholen">                     </div>                     <div id="email-group" class="form-group">                         <label for="email">e-mail</label>                         <input type="email" name="email" id="email" class="form-control" placeholder="e-mail">                     </div>                     <input type="submit" name="submit" id="submit" class="btn btn-default" value="registrieren">                 </div>             </fieldset>         </form>     </div> 

i'm using bootstrap, don't think that's problem. , code looks fine too.

it looks post code; please add more details.

if add error logging

error_reporting(e_all); ini_set('display_errors','on'); 

you see this:

deprecated: mysql_real_escape_string(): mysql extension deprecated , removed in future: use mysqli or pdo instead in .../public_html/index.php on line 38

warning: mysql_real_escape_string(): access denied user 'www-data'@'localhost' (using password: no) in .../public_html/index.php on line 38

mysql_real_escape_string requires connect database first. indeed function deprecated.

you can start deleting mysql_real_escape_string code see works.