How to call a php file with ajax post

Question

//File inserirPF.js

function add(){  
   var metodo = 'AdicionaPessoa';
   $.ajax({
     url: "../class/dao/InserirPFDao.class.php",
     type: 'POST',
     data: {Metodo:metodo, NOME_:NOME, EMAIL_:EMAIL, SENHA_:SENHA},
     success: function(data) {
        alert(data); 
     }
   });
 }

//File InserirPFDao.class.php

<?php 
require_once("../class/dao/connection.class.php");  

class InserirPFDao extends ConexaoMySQl
{

    function __construct(){
        parent::Connection();
        if (isset($_POST['Metodo'])) {
        switch ($_POST('Metodo')) {
            case 'AdicionaPessoa':
                $retorno = AdicionaPessoa();
                mysql_close($db);
                echo $retorno;
                break;
            default:
                echo "Nenhum metodo encontrado!"
                break;
            }
        }
    }

    public function AdicionaPessoa(){
        try {
            $NOME_ = $_POST("NOME_");
            $EMAIL_=$_POST("EMAIL_");
            $SENHA_=$_POST("SENHA_");
            $Adiciona = mysql_query("INSERT INTO PESSOA (NOME, EMAIL, SENHA)VALUES('".$NOME_."','".$EMAIL_."','".$SENHA_."')");
            if($Adiciona) 
                return true;
            else
                return false; 

        } 
        catch (Exception $e) {

        }           
    }
 }
 ?>

How to call a jQuery arquivoEstou trying to make the connection between Javascript and php with ajax. if anyone knows another way to do ... For showing this to me this error:

<font size='1'>
<table class='xdebug-error xe-parse-error' dir='ltr' border='1' cellspacing='0' cellpadding='1'>
    <tr>
    <th align='left' bgcolor='#f57900' colspan="5">
    <span style='background-color: #cc0000; color: #fce94f; font-size: x-large;'>( ! )</span> 
    Parse error: syntax error, unexpected T_PUBLIC in C:\Arquivos de programas\VertrigoServ\www\gofinder\class\dao\InserirPFDao.class.php on line 
    <i>7</i>
    </th>
    </tr>
</table>

Answer 1

$retorno = AdicionaPessoa(); doesn't look right. I'm guessing you meant:

$retorno = $this->AdicionaPessoa();

And as noted in the comments, you are creating a class but doing nothing with it. You need to instantiate the class. Add the following to the end of your file:

$inserirPFDao = new InserirPFDao();

You might want to have a read of some basic Object Oriented Programming tutorials to help you get started. You look like you are mixing OO and procedural code without understanding the differences.

Have a read through some of these: http://net.tutsplus.com/tutorials/php/object-oriented-php-for-beginners/