[Catchable fatal error]

Hello everyone! 

 

I'm having issues with a delete button on a table row, im getting this error: 

 

Catchable fatal error: Object of class mysqli could not be converted to string in C:\xampp\htdocs\consultas\newdatapull.php on line 19

 

I'm not sure whats going on, here's my code: 

<?php
include('header.php');

$servername = "localhost";
$username = "un";
$password = "admin";
$dbname = "emelyconsultas";

// Create connection
$conn = new mysqli($servername, $username, $password, $dbname);
// Check connection
if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error);
}; 

if (isset($_POST['delete'])) {

$deleteQuery = "DELETE FROM hoteles WHERE id='$_POST[delete]'";
mysqli_query("$conn, $deleteQuery, ");
};



$sql = "SELECT id, Full_Name, Email_Address, Telephone_Number, pais, ciudad, nombre_hotel, fecha_in, Fecha_out, adultos, ninos, mensaje FROM hoteles";
$result = $conn->query($sql);

if ($result->num_rows > 0) {

	echo "<div class='container-fluid'>
	<div class='col-md-12'>
		<div id='datatable'class='table-responsive well'>
			<h1 class='text-center'>Entradas</h1>
			<table id='table' class='table'>
			<tr>
			<th>ID</th>
			<th>Nombre</th>
			<th>Correo Electronico</th>
			<th>Numero Telefonico</th>
			<th>Pais Destinado</th>
			<th>Ciudad Destinada</th>
			<th>Hotel</th>
			<th>Check In</th>
			<th>Check Out</th>
			<th>Adultos</th>
			<th>Niños</th>
			<th>Mensaje</th>
			</tr>";
    // output data of each row
   while($row = $result->fetch_assoc()) {
        echo "<form action=newdatapull.php method=post>";
        echo "<tr>";
        echo "<td>" .$row['id'] . " </td>";
        echo "<td>" .$row['Full_Name'] . " </td>";
        echo "<td>" .$row['Email_Address'] . " </td>";
        echo "<td>" .$row['Telephone_Number'] . " </td>";
        echo "<td>" .$row['pais'] . " </td>";
        echo "<td>" .$row['ciudad'] . " </td>";
        echo "<td>" .$row['nombre_hotel'] . " </td>";
        echo "<td>" .$row['fecha_in'] . " </td>";
        echo "<td>" .$row['Fecha_out'] . " </td>";
        echo "<td>" .$row['adultos'] . " </td>";
        echo "<td>" .$row['ninos'] . " </td>";
        echo "<td>"  .$row['mensaje'] . " </td>";
        echo "<td>"  .$row['id'] . " </td>";
        echo "<td>" ."<input class=input-group type=submit name=delete value=Borrar>" . "</td>";
        "</form>";
        echo "</tr></table></div></div></div>";
    }
} 

else {
    echo "0 results";
}
$conn->close();
include('footer.php');
?>

thanks in advance to anyone that can help, Error comes up once I click the Delete button on the row...