my suggestion would be like this.

$(function () {
    var counter = 0;

    $('a').click(function () {
        var elems="<div>"+
              '<input type="checkbox" id="checkbox"' + (counter) + '" class="item"/>' + 
              '<input type="text" id="t1"' + (counter) + '"/>' +
              '<input type="button" class="removebtn" value="." id="removebtn"' + (counter) + '"/>' +
        '</div>';
        $('#box').append(elems);
        $("#box").append("<br />");
        $("#box").append("<br />");
        counter++;
    });

    $('.removebtn').live(function () {
        $(this).parent().remove();   
    });
});

simple demo