please check my code in connecting with localhost (using phpmyadmin xampp)

Question

<? php

$username="root";
$password="";
$db="NSH";
$Name=$_POST['Name'];
$conn=new mysqli($localhost,$username,$password,$db) or die("unable to connect");

$sql="insert into NSH('Name')";
values('$Name');
$query=mysqli_query($conn,$sql);
if($query)
{
echo "Data inserted";
}
else
{
echo "problem";
}

?>
//I connected this with my html file(form)..using action and also method as post

Answer 1

$localhost is not defined .
Do this $conn = mysqli_connect(localhost,"root","","NSH");