recover from that IP sends an email (addnew.php)

Hello,
it is possible to add a code to retrieve IP of the sender
a customer review?

I feel that something is missing in this variable because I am not able to retrieve the IP with my php scripts. For moemnt I:

PHP code
$print(“Votre adresse IP est : $_SERVER[‘REMOTE_ADDR’]”);

before
// Code for sending email When a new testimonial has-been Added
after

		// Code for sending mail when a new testimonial has been Added
		if ( $rset && mysqli_affected_rows($link)>0 ) {
			$to     	= $useremail;                    
			$subject 	= 'Nouveau Témoignage Ajouté';
			$message 	= "Témoignage Détails". "\r\n" ;
			$message 	.='Nom du client :'.stripslashes( $client_id ). "\r\n" ;
			$message 	.='Témoignage :' .stripslashes( $feedback ). "\r\n" ;
			$headers 	= 'De:' .$to . "\r\n" ;
			@mail( $to, $subject, $message, $headers );
			$successmsg	 = 	"Témoignage a été ajouté avec succès.";
                        $print("Votre adresse IP est : $_SERVER['REMOTE_ADDR']");

issue here
add the function id #checkbox

		else if (jQuery("#checkbox").prop("checked")==false) {
	        alert("Cochez cette case si vous acceptez les termes et conditions.");
	        frm.checkbox.focus();
	        return false;			
         }

add “name” checkbox and “id” checkbox
code is correct

								<div class="item">
									<div class="checkbox">
										<label>
										<input type="checkbox" name="checkbox" id="checkbox" > En continuant, vous acceptez les <a href="cgu.php"><span class="skin-color">Conditions générales</span></a>.
										</label>
									</div>
							   </div>

thank you