Order Placing Again And Again

While I am running my Code


<?php
//include_once ('include/db.php');
require_once('include/db.php');
require_once('include/function.php');
require_once('include/kiteconnect.php');

$access_token ="xxxxxxxxxxxxxxxxxxxxxxx";

$kite = new KiteConnect("xxxxxxxxxxxxxxxxxxxxx");


$kite->setAccessToken($access_token);


$order_id = $kite->orderPlace([
"tradingsymbol" => "BHEL",
"exchange" => "NSE",
"quantity" => 1,
"transaction_type" => "BUY",
"order_type" => "MARKET",
"product" => "NRML"
], "regular");

echo "Order id is ".$order_id;




?>