is this code right to connect html form to my sql using php

<?php
     $con=mysqli_connect("localhost","root","****","inquiry_box");

// Check connection
if (mysqli_connect_errno()) {
  echo "Failed to connect to MySQL: " . mysqli_connect_error();
}

// escape variables for security
$name = mysqli_real_escape_string($con, $_POST['name']);
$email = mysqli_real_escape_string($con, $_POST['email']);
$contact_no = mysqli_real_escape_string($con, $_POST['contact_no']);
$comment = mysqli_real_escape_string($con, $_POST['comment']);

$sql="INSERT INTO form (name, email, contact_no, comment)
VALUES ('$name', '$email', '$contact_no', '$comment')";

if (!mysqli_query($con,$sql)) {
  die('Error: ' . mysqli_error($con));
}
echo "1 record added";

mysqli_close($con);
?>