AJAX返回数据PHP / MySQL

I have an insert function on my page that uses AJAX/PHP to insert data into myMySQL table, When a row of data is added, my row of data is returned and printed out inside...

 <div id="bills"></div>

I can then add another row of data, When i do this however it overwrites the contents of #bills, is there a way to add it to the information in there as opposed to overwriting that?

AJAX

function insertBill()
{
    $.post('insert_bill.php', $('form').serialize(), 
        function(data) {***
        $("#bills").html(data); 
    });
}

$('#bills').append(data);

jQuery.fn.append documentation

Instead of .html() use .append()

$("#bills").append(data);

data can contain html tags and jQuery will do the right thing.

Yes:

$("#bills").append(data);