Setting the innerHTML of a div to information retrieved from a MySQL database (using AJAX/PHP)?

On my page (index.php), I have a content-editable div with id = "name" and a content-editable div with id = "info". I also have a button with id = "save" and a button with id = "lookUp".

in index.php:

<p> <div> Name: </div> <div id="name" contenteditable="true"> </div> </p>
<p> <div> Info: </div> <div id="info" contenteditable="true"> </div> </p>

<p>
    <button id="save" type="button" style="float: left;" class="buttonText"> Save </button>
    <button id="lookUp" type="button" style="float: left;" class="buttonText"> Look Up </button>
</p>

I would like the page to be able to do two things:

1) If the user clicks the 'Save' button and both content-editable divs are filled, the name and info entered into the content-editable divs by the user are saved to a two-column table (columns: "name" and "info") in a local MySQL database. I have already implemented this functionality with AJAX/PHP, and it works without error.

2) If the user clicks the 'Look Up' button, then I would like the text entered into the content-editable div with id = "name" (the innerHTML of the name div) to be looked up in the database. If the name is found, I would like the site to retrieve the text stored in the corresponding entry's 'info' column and enter it into the content-editable div with id = "info" (set the innerHTML of the 'info' div to the retrieved info).

So far I have partially implemented 2) with the following code:

in index.php:

<script type="text/javascript">
    $(document).ready(function(argument) 
    {
        $('#lookUp').click(function()
        {
            $name = $('#name').html();
            $info = $('#info').html();

            $.ajax(
            {
              url: 'lookup.php', type: 'post', data: {nameSubmit: $name}, datatype: 'html', success: function(rsp){alert(rsp);}
            });
        });
    });
</script>

in lookup.php:

<?php 

    $name = $_POST['nameSubmit'];
    $name = mysql_real_escape_string($name);

    $connect = mysql_connect( "localhost", "localUserName", "localPassword", "" );
    $selectedDB = mysql_select_db("nameInfoDatabase", $connect);

    $lookup = "SELECT * FROM nameInfoTable";
    $lookupResults = mysql_query( $lookup, $connect );

    $nameFound = FALSE;

    while($record = mysql_fetch_array($lookupResults))
    {
        if( $record['name'] == $name )
        {
            $nameFound = TRUE;
            $info = $record['info'];
        }
    }   

    if( $nameFound ){ echo "Account Located.  Info: " . $info; }
    else{ echo "FAILURE: Name not found!"; }

    // NOW WHAT?
?>

After a "Look Up" button-click, the information I want to be saved to the innerHTML of the div with id = "info" in index.php is saved to the variable $info in lookup.php. This $info is correctly printed (echoed) to the dialogue pop-up, but I want it to be entered into the content-editable, id = "info" div of the index.php page. How do I proceed?

I have tried things like echoing lines of javascipt, as is discussed here and here, but I have not been able to get it working with existing StackOverflow Q&As. I am sorry if this question is overly basic or has already been addressed in a way that I did not understand, I am very new to PHP and back-end development.

Thanks for the help! Jack