$captcha = $_POST['g-recaptcha-response'];
$response = file_get_contents("https://www.google.com/recaptcha/api/siteverify?secret=IDEJONASECRETKULCS&response=".$captcha."&remoteip=".$_SERVER['REMOTE_ADDR']);
$data = json_decode($response);

if(isset($data->success) and $data->success == 1){
		//SIKER
}else{
		//A captcha nem lett kitöltve
}