borang

<?php
// Include config file
require_once "config.php";

// Define variables and initialize with empty values
$nameid = $address = $phone = "";
$nameid_err = $address_err = $phone_err = "";

// Processing form data when form is submitted
if($_SERVER["REQUEST_METHOD"] == "POST"){

    // Validate username
    if(empty(trim($_POST["nameid"]))){
        $nameid_err = "Please enter your name.";
    } else{
        // Prepare a select statement
        $sql = "SELECT id FROM borang WHERE nameid = ?";
       
        if($stmt = mysqli_prepare($link, $sql)){
            // Bind variables to the prepared statement as parameters
            mysqli_stmt_bind_param($stmt, "s", $param_nameid);
           
            // Set parameters
            $param_nameid = trim($_POST["nameid"]);
           
            // Attempt to execute the prepared statement
            if(mysqli_stmt_execute($stmt)){
                /* store result */
                mysqli_stmt_store_result($stmt);
               
                if(mysqli_stmt_num_rows($stmt) == 1){
                    $nameid_err = "This name is already taken.";
                } else{
                    $nameid = trim($_POST["nameid"]);
                }
            } else{
                echo "Oops! Something went wrong. Please try again later.";
            }
        }
// Validate address
        if($stmt = mysqli_prepare($link, $sql)){
            // Bind variables to the prepared statement as parameters
            mysqli_stmt_bind_param($stmt, "s", $param_address);
           
            // Set parameters
            $param_address = trim($_POST["address"]);
           
            // Attempt to execute the prepared statement
            if(mysqli_stmt_execute($stmt)){
                /* store result */
                mysqli_stmt_store_result($stmt);
               
                if(mysqli_stmt_num_rows($stmt) == 1){
                    $address_err = "This address is already taken.";
                } else{
                    $address = trim($_POST["address"]);
                }
            } else{
                echo "Oops! Something went wrong. Please try again later.";
            }
        }

// Validate phone
        if($stmt = mysqli_prepare($link, $sql)){
            // Bind variables to the prepared statement as parameters
            mysqli_stmt_bind_param($stmt, "s", $param_phone);
           
            // Set parameters
            $param_address = trim($_POST["phone"]);
           
            // Attempt to execute the prepared statement
            if(mysqli_stmt_execute($stmt)){
                /* store result */
                mysqli_stmt_store_result($stmt);
               
                if(mysqli_stmt_num_rows($stmt) == 1){
                    $phone_err = "This phone is already taken.";
                } else{
                    $phone = trim($_POST["phone"]);
                }
            } else{
                echo "Oops! Something went wrong. Please try again later.";
            }
        }
       
        // Close statement
        mysqli_stmt_close($stmt);
    }
   
   
    // Check input errors before inserting in database
    if(empty($nameid_err) && empty($address_err) && empty($phone_err)){
       
        // Prepare an insert statement
        $sql = "INSERT INTO borang(nameid, address, phone) VALUES (?, ?, ?)";
       
        if($stmt = mysqli_prepare($link, $sql)){
            // Bind variables to the prepared statement as parameters
            mysqli_stmt_bind_param($stmt, "sss", $param_nameid, $param_address, $param_phone);
           
            // Set parameters
            $param_nameid = $nameid;
$param_address = $address;
$param_phone= $phone;
           
           
            // Attempt to execute the prepared statement
            if(mysqli_stmt_execute($stmt)){
                // Redirect to login page
                header("location: login.php");
            } else{
                echo "Something went wrong. Please try again later.";
            }
        }
       
        // Close statement
        mysqli_stmt_close($stmt);
    }
   
    // Close connection
    mysqli_close($link);
}
?>

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Sign Up</title>
    <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.css">
    <style type="text/css">
        body{ font: 14px sans-serif; }
        .wrapper{ width: 350px; padding: 20px; }
    </style>
</head>
<body>
    <div class="wrapper">
        <h2>Registration Form</h2>
        <p>Please fill this form.</p>
        <form action="<?php echo htmlspecialchars($_SERVER["PHP_SELF"]); ?>" method="post">
            <div class="form-group <?php echo (!empty($username_err)) ? 'has-error' : ''; ?>">
                <label>Name</label>
                <input type="text" name="nameid" class="form-control" value="<?php echo $nameid; ?>">
                <span class="help-block"><?php echo $nameid_err; ?></span>
            </div> 
            <div class="form-group <?php echo (!empty($username_err)) ? 'has-error' : ''; ?>">
                <label>Address</label>
                <input type="text" name="address" class="form-control" value="<?php echo $address; ?>">
                <span class="help-block"><?php echo $address_err; ?></span>
            </div>
            <div class="form-group <?php echo (!empty($username_err)) ? 'has-error' : ''; ?>">
                <label>Phone Number</label>
                <input type="text" name="phone" class="form-control" value="<?php echo $phone; ?>">
                <span class="help-block"><?php echo $phone_err; ?></span>
            </div>
           
           
            <div class="form-group">
                <input type="submit" class="btn btn-primary" value="Submit">
                <input type="reset" class="btn btn-default" value="Reset">
            </div>
           
        </form>
    </div>   
</body>
</html>