Undefined Index Name when trying to pass values from Jquery to PHP

Question

So, I'm working on figuring out how to post data from Jquery to PHP, And as much as I follow the examples I've found on the threads here, I keep getting an "Undefined Index Name" error.

My code thus far for the JQuery side is

<script src="jquery-1.11.1.min.js"></script>
</script>
<script>
$(document).ready(function(){
     $("#div2").text('Hey');
    $("#div1").load('testFile.txt');
    setInterval(function() {
    $.ajax({ url: 'script.php' });
    $("#div1").load('testFile.txt');}
    ,100);



  });
  function sub(){

     var msg = $("#name").val();

     $.post('chat.php',{'name':"1234"},function(){
$("#div2").load('chat.php');
});  
 };

</script>

The html forms and buttons I'm using

<div id="div1"></div>
<div id="div2">Um</div>

<form name="myForm" id="myForm" action="" method="POST">
<input type="text" name="name" id="name" size="30" value=""/>
</form>
<button id="submission" onclick="javascript:sub();">Errrr</button>

And the PHP side I'm going to

<?php
echo $_POST['name'];
 $myFile = "testFile.txt";
 $fh = fopen ($myFile, 'a+') or die("Cannot Open File");
 fwrite ($fh, $_POST['name']);
 fclose($fh);

?>

I'm about at a loss from where to do. All files are within the same folder and filenames are correct as far as I can find.

Answer 1

Your issue is most likely that you're doing this:

$.post('chat.php',{'name':"1234"},function(){
    $("#div2").load('chat.php');
});  

You're effectively sending the data {'name': '1234'} to the file and then just loading the file? You'll get the error because you load() the file without sending it params.

Looking at the jQuery.post manual, you'd see that you can get a response with something like this:

$.post('chat.php',{'name':"1234"},function(data){
    console.log(data);
}); 

While you use something like echo or print to effectively "return" content to the ajax call.

<?php
echo $_POST['name'];
?>

Now check in your console and see if there is a response.