php code returning as source code on the browser

Question

Hie.My php code is returning as the actual code on my browsers.its not giving output.it just show the code as it is.

<?php
$servername = "localhost";
$username = "root";
$password = "";


$db_name="agric";
// Create connection
$conn = new mysqli_connect("$servername", "$username", "$password",);
mysql_select_db($db_name)or die("Could not connect to database");

// Check connection
if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error);
} 
echo "Connected successfully";
?>

my database is agric and i created it using xampp.Can someone help me with a solution.