Automatic Form Completed With PHP Ajax - php

Question

I have two textboxes namely no_id and customer_name. when the user enters no_id, customer_name is filled in automatically.
Form
<form>
<input type="text" name="no_id" onkeyup="autofill()" id="no_id">
<input type="text" name="customer_name" id="customer_name" readonly>
<!--textbox customer_name is readonly-->
</form>
Javascript
<script type="text/javascript">
function autofill(){
var no_id = $("#no_id").val();
$.ajax({
url: 'ajax.php',
data:"no_id="+no_id ,
}).success(function (data) {
var json = data,
obj = JSON.parse(json);
$('#customer_name').val(obj.customer_name);
});
}
</script>
ajax.php
include 'conn.php';
$npwp = $_GET['no_id'];
$query = mysqli_query($conn, "select * from ms where no_id='$no_id'");
$ms = mysqli_fetch_array($query);
$data = array(
'customer_name' => $ms['customer_name']);
echo json_encode($data);
The scripts above works for me.
Now I want to modify it.
When the no_id entered is NOT stored in the database, the customer_name box attribute becomes readonly=false, so the user can fill in customer_name box.

Answer 1

you can use jquery onChange method on no_id input to send no_id value and search it's stored in the database or not and return true or false (0 or 1)like this code:
$('#no_id')onchange(function(){
var no_id = $(this).val();
$.ajax({
url: 'ajax.php',
data:"no_id="+no_id ,
}).success(function (data) {
if(data == true){
$('#customer_name').attr('readonly');
}else if(data == false){
$('#customer_name').removeAttr('readonly');
}
});
});
I prefer to create another function for no_id onChange method

Answer 2

Here I am counting rows in mysql and if rows == 0, then removing readonly attribute
Javascript
<script type="text/javascript">
function autofill(){
var no_id = $("#no_id").val();
$.ajax({
url: 'ajax.php',
data:"no_id="+no_id ,
success : function (data) {
var json = data;
obj = JSON.parse(json);
if(obj.success=='true') {
$('#customer_name').val(obj.customer_name).attr("readonly", true);
} else {
$('#customer_name').val("").attr("readonly", false);
}
}
})
}
</script>
AJAX.php
include 'conn.php';
$npwp = $_GET['no_id'];
$query = mysqli_query($conn, "select * from ms where no_id='$npwp'");
if(mysqli_num_rows($query) >= 1 ) {
$ms = mysqli_fetch_array($query);
$data = array('customer_name' => $ms['customer_name'], 'success'=>'true');
echo json_encode($data);
} else {
$data = array('success'=>'false');
echo json_encode($data);
}