Validate Dynamically Form Data - php

Question

I have a form field in my site that I need to know if the email that the user want to use isn't already used by other user.
I am using JavaScript and PHP for that but can make it work.
function validateEmail(){
//testing regular expression
var a = $("#email").val();
var filter = /^[A-Z0-9._%+-]+#[A-Z0-9.-]+\.[A-Z]{2,6}$/;
//if it's valid email
if(filter.test(a)){
if($("#email").val() != ""){
$.getScript("http://localhost/sisdelivery/validaEmail.php?&email="+$("#email").val(), function(){
if(resultadoEmail["email"] != ""){
email.addClass("error");
emailInfo.text("Email ja cadastrado!");
emailInfo.addClass("error");
return false;
}
else{
email.removeClass("error");
emailInfo.text("Email OK");
emailInfo.removeClass("error");
return true;
}
}
}
}
//if it's NOT valid
else{
var valEmail = $("#email").val();
if(valEmail == ""){
email.addClass("error");
emailInfo.text("Favor digitar um email!");
emailInfo.addClass("error");
return false;
}
else{
email.addClass("error");
emailInfo.text("O email digitado e invalido");
emailInfo.addClass("error");
return false;
}
}
}
The PHP code that looks on the database for the data:
<?php
include "conecta.php";
$email = $_GET['email'];
$consulta = "SELECT * FROM usuarios WHERE email = '$email';";
$result = mysql_query($consulta);
$num = mysql_num_rows($result);
if($num == 0)
echo "var resultadoEmail = { 'email' : '' }";
else{
while($row = mysql_fetch_object($result)){
$email = $row -> email;
}
echo "var resultadoEmail = { 'email' : '$email' }";
}
?>
I'm getting the error Uncaught SyntaxError: Unexpected token } but can't find where is the problem.

Answer 1

First of all, I just want to tell you that you have a security risk in your code. This line :
$email = $_GET['email'];
$consulta = "SELECT * FROM usuarios WHERE email = '$email';";
allow a person to run sql against your database and retrieve data. This is know as sql injection. You should validate your email before doing your query at minimum.

Answer 2

use this
return true;
}
});
^^^ // you forgot this