jquery 新建的元素事件绑定问题

<p class="file">图片标题：<input type="text" name="attachment_title[]" style="width:8em" /><input class="attachment" type="file" name="attachment[]" /><input type="button" class="del_attachment" value="删除"></p> <mce:script type="text/javascript"><!-- var attachment_count = 1; var attachment_change = function(){ if(attachment_count >= 3){ return false; } if($(this).parent().next().attr('class') != 'file'){ $(this).parent().after($(".file:first").clone(true).find(".attachment").change(attachment_change).end()); } attachment_count++; } $(".attachment").change(attachment_change) $(".del_attachment").click(function(){ $(this).parent().remove(); attachment_count--; }) // --></mce:script>