You forget signle quote and )
in the_name
input.
<input type="text" name="the_input" value="<?php if (isset($_POST['the_input'])) { echo $_POST['the_input'] ; } ?>">
and for getting form button pressed value you need to append it value manually to serialize.
$form.serialize() + "&submit="+ $('button').attr("value")
Example
<script type="text/javascript">
$(function()
{
$('button[type="submit"]').on('click',function(e)
{
e.preventDefault();
var submit_value = $(this).val();
jQuery.post
(
$(this).attr('action'),
$(this).serialize()+ "&submit="+ submit_value,
function(data)
{
$('#result').empty().append(data).slideDown();
}
);
});
});
</script>
Complete Tested Code
<?php
if(isset($_POST['the_input']))
{
$input = $_POST['the_input'];
$eating = $_POST['eat_something'];
exit;
}
?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">
<head>
<meta http-equiv="Content-Type" content="text/html;charset=UTF-8" />
<title>StackOverFlow</title>
<script type="text/javascript" src="js/jquery.js"></script>
<script type="text/javascript">
$(function()
{
$('button[type="submit"]').on('click',function(e)
{
e.preventDefault();
var submit_value = $(this).val();
jQuery.post
(
$('#the-form').attr('action'),
$('#the-form').serialize()+ "&eat_something="+ submit_value,
function(data)
{
$('#result').empty().append(data).slideDown();
}
);
});
});
</script>
</head>
<body>
<form method="post" action="random.php" id="the-form">
<input type="text" name="the_input" value="<?php if (isset($_POST['the_input'])) { echo $_POST['the_input'] ; } ?>">
<button type="submit" name="eat_something" value="TRUE">Eating</button>
<button type="submit" name="eat_something" value="FALSE">Don't Eat</button>
</form>
<textarea id="result"></textarea>
</body>
</html>