Untitled

<body>

<form action="" method"post" class="form">
<div class="form-group1">
<label for="" >Username :</label>
<input type="text" class="form-control" name="username" id="tb-username" placeholder="Username">
</div>
<div class="form-group2">
<label for="" >Password :</label>
<input type="password" class="form-control" name="password" id="tb-password" placeholder="Password">
</div>
<button type="submit" class="btn btn-primary" id="btn-submit" name="register">Submit</button>
</form>

<?php

if(isset($_POST['register']))
{
if(isset($_POST['username'], $_POST['password']))
{
    $username = $_POST['username'];
    $password = $_POST['password'];

    $link = mysqli_connect("localhost", "root", " ", "vbproject");

    if(mysqli_connect_errno())
    {
        printf("Connect failed: %sn", mysqli_connect_errno());
        exit();
    }

    $sql = "INSERT INTO users (username, password)
            VALUES('$username', '$password')";

    mysqli_close($link);
}
}
 ?>

</body>