Why won't this snippet of code work?

Question

I'm trying to set character limits for a register page and no matter what it says the username is too long can you guys tell me what's wrong? see the error for your self

    if(mb_strlen($uname) >= 20){
    if(mb_strlen($uname) <= 6){
    if(mb_strlen($pass1) <= 8){
    if(mb_strlen($pass1) >= 16){
    if((mb_strlen($email)) > 5 && strstr(($email1), "@") && strstr(($email1),".")){
        $pass = md5(md5("47Jdfio209".$pass1."4jfhioJasify3"));
        $pass = hash('sha512',$pass);


    $sql = $mysqli -> query("SELECT * FROM `archewor_users`.`users` WHERE `uname` = '$uname'");
    if(mysqli_num_rows($sql) > 0){
        echo"Sorry, that user already exists.";
    exit();

    }
    $mysqli -> query("INSERT INTO `archewor_users`.`users` (`id`, `name`, `lname`, `uname`, `email`, `pass`) VALUES (NULL, '$name', '$lname', '$uname', '$email1', '$pass')") or die(mysqli_error());
    }else{echo 'Your email must be valid.';}
    }else{echo 'This password is too long';}    
    }else{echo 'This password is too short';}
    }else{echo 'This username is too short';}

    }else{echo 'This username is too long';}

}else{
    echo "Sorry, your passwords do not match.<br />";   
    exit();
    }
}else{
    echo "Sorry, your emails do not match. <br /> <br />";
}




}else{

Answer 1

Logics written by you is incorrect. Check your if conditions for both username and passwords validation. Written code has very poor standard. Use conditional operators instead of nested if conditions.

Answer 2

It's only a logical error

// 1. Here you check, if your username is to LONG
// So your -else- is called, if your username is to SHORT
if(mb_strlen($uname) >= 20){
  // all the rest
} else {echo 'This username is too long';} // This message should be "Username is to short"

Maybe better:

if(mb_strlen($uname) >= 20)
  die("Username is to long");

if(mb_strlen($uname) <= 6)
  die("Username is to short");