I'm trying to run this function to check if the database has the same email

Question

function runthis(){
        var email = $("#email").val();

          var xmlhttp = new XMLHttpRequest(); 
            var url = serverURL() + "/Achecksameemail.php"; 
                url += "?email=" + email;

        xmlhttp.onreadystatechange=function() { 
                if (xmlhttp.readyState == 4 && xmlhttp.status == 200) { 
            runthisResult(xmlhttp.responseText);
                 } 
            }
            xmlhttp.open("GET", url, true);
            xmlhttp.send();   
        }


    function runthisResult(response) {
        var arr = JSON.parse(response);     
        for(var i=0; i < arr.length;i++){

            if(arr[i].email = $("#email").val()){
            alert("This email has already been used. Please use another email.");

        }

        else { 
            savenewuser();
        }
    }

}       

However, when it checks that the email has not been used, it can't run the second function to save the user details to the database. Anyone know why? Thank You!

Answer 1

Check email existing and validation in Achecksameemail.php

$response = [
    'exists' => TRUE,
    'msg'    => ''
];

if(filter_var($_GET['email'], FILTER_VALIDATE_EMAIL))
{
    $select = mysql_query("SELECT `email` FROM `users` WHERE `email` = '".$_GET['email']."'");

    if(mysql_num_rows($select))
        $response['msg'] = 'This email is already being used';
    else
        $response['exists'] = FALSE; 
}
else
{
    $response['msg'] = 'Invalid email address!';
} 

echo json_encode($response);

And response in js

function runthisResult(response)
{
    response = JSON.parse(response);     

    if(response.exists)
        alert(response.msg);
    else
        savenewuser();
}