实时用户名验证不起作用

Question

您好我正在尝试使用ajax验证电子邮件和用户名，但相同的代码不适用于两个不同的inupt字段。

HTML

<script>

    //function to check username availability
    function check_availability_username(){

        //get the username
        var username = $('.username').val();

        //use ajax to run the check
        $.post("check_username.php", { username: username },
            function(result){
                //if the result is 1

                if(result == 1){
                    //show that the username is available
                    $('#username_availability_resul1').html('<span style="color:#0C0;">'+username + ' is available!</span>');
                }else{
                    //show that the username is NOT available
                    $('#username_availability_result').html('<span style="color:#F00;">'+username +result+ ' already used!</span>');
                }
            });

    }

    function check_availability(){

        //get the username
        var email = $('.email').val();

        //use ajax to run the check
        $.post("check_email.php", { email: email },
            function(result){
                //if the result is 1
                if(result == 1){
                    //show that the username is available
                    $('#email_availability_result').html('<span style="color:#0C0;">'+email + ' is available!</span>');
                }else{
                    //show that the username is NOT available
                    $('#email_availability_result').html('<span style="color:#F00;">'+email + ' already used!</span>');
                }
            });

    }

</script>
<form role="form" method="post" action="add-users.php?insert=ok" class="form-horizontal form-groups-bordered">

    <div class="form-group">
        <label for="field-1" class="col-sm-2 control-label">Username</label>

        <div class="col-sm-6">
            <input type="text" onkeyup="check_availability_username()" class="form-control" name="username" placeholder="Username1" required>
            <div id='username_availability_result'></div>
        </div>
    </div>


    <div class="form-group">
        <label for="field-1" class="col-sm-2 control-label">Email Address</label>

        <div class="col-sm-6">
            <input type="email" onkeyup="check_availability()" class="form-control email"  name="email" placeholder="Email Address" required>
            <div id='email_availability_result'></div>
        </div>
    </div>



        <div class="form-group">
        <div class="col-sm-offset-2 col-sm-6">
            <input type="submit" class="btn btn-primary" value="Add User">
            <input class="btn btn-danger" type="reset" value="Reset">

        </div>
    </div>

    </form>

check_username.php

<?php
//connect to database  
$db = mysqli_connect('localhost', 'root', '123', 'mydb') or die('db not connected');

//get the username  
$username = mysqli_real_escape_string($db, $_POST['username']);

//mysql query to select field username if it's equal to the username that we check '  
$result = mysqli_query($db, 'select username from userinfo where username = "'. $username .'"');



//if number of rows fields is bigger them 0 that means it's NOT available '  
if(mysqli_num_rows($result)>0){
    //and we send 0 to the ajax request  
    echo 0;
}else{
    //else if it's not bigger then 0, then it's available '  
    //and we send 1 to the ajax request  
    echo 1;
}

?>

check_email.php

<?php
//connect to database  
$db = mysqli_connect('localhost', 'root', '123', 'mydb') or die('db not connected');
  
//get the email 
$email = mysqli_real_escape_string($db, $_POST['email']);  
  
//mysql query to select field email if it's equal to the email that we check '  
$result = mysqli_query($db, 'select email from userinfo where email = "'. $email .'"');
  
//if number of rows fields is bigger them 0 that means it's NOT available '  
if(mysqli_num_rows($result)>0){  
    //and we send 0 to the ajax request  
    echo 0;  
}else{  
    //else if it's not bigger then 0, then it's available '  
    //and we send 1 to the ajax request  
    echo 1;  
}  

?>

代码适用于EMAIL验证，但不适用于USERNAME。

任何建议