Registration verification and authentication by ajax - php

Question

I have a registration form which when filled and "Register" button pressed is being checked by js, to find empty fields and to check availability of username, or if email or mobile num was already used by sending info through ajax to php and receiving answer. But my js won't work all the way through. This is my js script:
$("#reg_button").click(function(){
user = $("#usr").val();
pass = $("#psw").val();
fname = $("#first_name").val();
sname = $("#second_name").val();
dateb = $("#date_birth").val();
email = $("#email").val();
mobnum = $("#mob_num").val();
if(user == ""){
alert("First name must be filled out");
$('#usr').focus();
return false;
}else if(pass == ""){
alert("Password must be filled out");
$('#psw').focus();
return false;
}else if(fname == ""){
alert("First name must be filled out");
$('#first_name').focus();
return false;
}else if(sname == ""){
alert("Second name must be filled out");
$('#second_name').focus();
return false;
}else if(dateb == ""){
alert("Date of birth must be filled out");
$('#date_birth').focus();
return false;
}else if(email == ""){
alert("Email must be filled out");
$('#email').focus();
return false;
}else if(mobnum == ""){
alert("Mobile number must be filled out");
$('#mob_num').focus();
return false;
}else{
ajaxCheck();
}
function ajaxCheck(){
$.ajax({
type: "POST",
url: "http://imes.*********.com/php/check_info_reg.php",
data: "usr="+user+"&email="+email+"&mob_num="+mobnum,
dataType: "json",
success: function(json){
if(json.success){
var user_conf = json.data.usr;
var email_conf = json.data.email;
var mob_conf = json.data.mob;
if(user_conf == "taken"){
alert("Username already taken. Choose another one.");
$('#usr').focus();
return false;
}
if(email_conf == "taken"){
alert("Email already registered. If you lost your password, retrieve it on login page.");
$('#email').focus();
return false;
}
if(mob_conf == "taken"){
alert("Mobile number already registered. If you lost your password, retrieve it on login page.");
$('#mob_num').focus();
return false;
}
}else{
//Here could go another ajax, for actualy sending the
//info into the php script which sends it to database.
}
},
beforeSend: function() { $.mobile.showPageLoadingMsg(); }, //Show spinner
complete: function() { $.mobile.hidePageLoadingMsg() }, //Hide spinner
});
return false;
}
});
And my php:
<?php
$username = mysql_real_escape_string($_POST['usr']);
$email = mysql_real_escape_string($_POST['email']);
$mob_num = mysql_real_escape_string($_POST['mob_num']);
include('mysql_connection.php');
mysql_select_db("jzperson_imesUsers", $con);
$sql1 = mysql_query("SELECT * FROM registered_user WHERE username='$username'");
$sql2 = mysql_query("SELECT * FROM registered_user WHERE email='$email'");
$sql3 = mysql_query("SELECT * FROM registered_user WHERE mobile_num='$mob_num'");
$res1 = mysql_num_rows($sql1);
$res2 = mysql_num_rows($sql2);
$res3 = mysql_num_rows($sql3);
if(isset($username) && !empty($username){
if($res1 >= 1){
//JSON message: Username already taken. Choose different.
echo json_encode(array('success'=>true, 'usr'=>"taken"));
}
}
elseif(isset($email) && !empty($email)){
if($res2 >= 1){
//JSON message: Email already registered. Retrieve on "login"(login => link).
echo json_encode(array('success'=>true, 'email'=>"taken"));;
}
}
elseif(isset($mob_num) && !empty($mob_num)){
if($res3 >= 1){
//JSON message: Mobile number already registered. Retrieve on "login"(login => link).
echo json_encode(array('success'=>true, 'mob'=>"taken"));
}
}
else{
echo json_encode(array('success'=>false));
}
?>

Answer 1

You are missing a parenthesis in your php file:
if(isset($username) && !empty($username){
Should be
if(isset($username) && !empty($username)){