Servicio web para servir contactos

contacts.php

<?php
/*
@author evilnapsis
*/
$con = new mysqli("localhost","root","","contactapp");

if(isset($_GET["opt"]) && $_GET["opt"]=="all"){
	$sql = "select * from contact";
	$query = $con->query($sql);
	$data = array();
	while($r = $query->fetch_assoc()){
		$data[] = $r;
	}
	echo json_encode($data);
}
else if(isset($_GET["opt"]) && $_GET["opt"]=="add"){
	$sql = "insert into contact (name,lastname,address,phone,email) values (\"$_POST[name]\",\"$_POST[lastname]\",\"$_POST[address]\",\"$_POST[phone]\",\"$_POST[email]\" )";
	$con->query($sql);
	echo json_encode(array("status"=>"success"))
}
?>