<div id="part2"></div>

<script type="text/javascript" >

$('#button').click(function ()
{
var text = $('#text').val();
var number = 2;
$.post('ajaxskeleton.php', {
red: text
},
    function(){
    $('#part' + number).html(text);
    });
});


</script>

$('#part' + number).html(text);

$(<a string>)

function(){
    alert(number + ":" + text);//or use console.log(number + ":" + text)
    $('#part' + number).html(text);
});

$.post('ajaxskeleton.php', {
    red: text
}, function(){
    $('#part' + number).html(text);
}).fail(function(jqXHR, textStatus, errorThrown) {
    console.log(arguments);
});