Unknown Error on Web Host but code runs well on localhost - php

Question

I just had finished a form working in my localhost, it was working perfectly, but by the time I uploaded the code to the web host it wasn't working as it was supposed to. It is a simple form that uses PHP, MySQL and JQuery. When I click on submit it shows my custom error window saying that the email was registered already but the thing is that the database is empty. I put some code inside the ajax part that checks the email and this is what it says (it's supposed to show only a number):
Warnings : mysql_fetch_assoc(): supplied argument is not a valid MySQL result resources in /*/*/public_html/check_user.php on line 17
Here's check_user.php:
<?php
require_once("SqlChromoConnection.php");
// Check if email is not empty in the form
if(isset($_POST['email'])) {
// create the query
$sql = "SELECT COUNT(*) AS count
FROM Users
WHERE email = '" . trim($_POST['email']) . "'";
// create object to handle the connection
$conn = new SqlChromoConnection();
$conn->getDatabaseConnection(); // establish a connection
$data = $conn->executeQuery($sql); // execute query
$count= mysql_fetch_assoc($data); // save result in $count
$exists = $count['count']; // access only the field 'count'
$conn->closeConnection(); // close the connection
echo $exists;
exit(0);
}
?>
And here's the ajax part that checks the email:
if( !re.test(email) || email.indexOf(' ') > 0) {
message = "Email NOT valid!!!";
messageDialog("Warning", message, "warning", 2);
return false;
} else {
// use ajax to check if a user has been previously registered
// using this email
var valid = false;
$.ajax(
{
url:"check_user.php", // url that will use
async: false,
data:{ // data that will be sent
email:email
},
type:"POST", // type of submision
dataType:"text", // what type of data we'll get back
success:function(data)
{
window.alert(data);
// if check_user returns 0
// means that there's no any user registered with that email
if(data == 0 ) {
valid = true;
}
}
});
if(!valid) {
message = "This email is registered already!";
messageDialog("Error", message, "error", 2);
return false;
}else return true;
}
As I said, the code runs well when in localhost.
Any suggestions will be really appreciated.
Regards.

Answer 1

Add # before your mysql_fetch_assoc it removes all warning comes from this statement.
Use like #mysql_fetch_assoc().

Answer 2

I think you should use users Instead of Users for table name