Bool（假）现场直播，但在localhost上工作

Question

I have this code on localhost and live hosting but always bool(false) bool(false) on live hosting when I fill up the text area of username and password but it adds up to the database of the hosting but no value in it because its false.

When I run it to my localhost its just fine displaying the results of the username, password and the hash value and adds up to the database.

<?php

include "db.php";
require "lib/password.php";

    if (isset($_POST['submit']))
    {       
                    $username= $_POST['leguser'] ;
                    $password= $_POST['legpass'] ;  
                    $pwhash = password_hash($password, PASSWORD_DEFAULT) ;
                    $username = mysql_real_escape_string($username);
                    $password = mysql_real_escape_string($password);

                    echo var_dump ($username);
                    echo var_dump ($password);
                    echo var_dump ($pwhash);

        $sql = "SELECT * FROM tbl_users WHERE fld_username = '$username'";
        $result = $conn->query($sql);
        if ($result->num_rows == true) { 
                         echo "<script>alert('Username already used!');</script>"; }
                    else
                    {                               
        $q = "INSERT INTO `tbl_users` (`fld_username`,`fld_password`) VALUES ('$username','$pwhash')";
            $result = $conn->query($q);
                if ($result) {
                    echo 'success';
                } else {
                    echo 'failure: ' . mysql_error(); 
                }
                    }            

}

?>

Thank you for the help in advance, I am just a beginner in this field :)