สอบถาม append() กับ html() หน่อยครับ พอดีผมทำ Page Scroll Ajax Jquery

function load_comment(limit,start){
		
		$.ajax({
			url:"<?php echo base_url('frontend/page_comment2/{lang_code}/');?>",
            type: 'post',
			data:{limit:limit, start:start},
            cache:false,
			beforeSend:function(response){
				$('#load').show();
			},
            success:function(response){
				
			$('#load').hide();	
			
			
			
			$('#display_comment').append(response);
			
			
			
			if(response == ''){
						$('#load_data_message').html("<button type='button' class='btn btn-info'>No Data Found</button>");
						action = 'active';
					}
					else
					{
						$('#load_data_message').html("<button type='button' class='btn btn-warning'>Please Wait....</button>");
                        action = "inactive";
					}
			
			
			
            }
		})
	}
	
	
	
	if(action == 'inactive'){
		action = 'active';
       
	
	}
 
 
	$(window).scroll(function(){
		
		
		if($(window).scrollTop() + $(window).height() > $("#display_comment").height() && action == 'inactive'){
		 action = 'active';
         start = start + limit;
         setTimeout(function(){
			load_comment(limit,start);
			
			 }, 1000);
	    }
		
	
		
		
	});