在社交网络网站上使用ajax刷新页面

I want to create a social network website. but there is a problem when the page refreshes the page with ajax. there I am using setInterval every 5 seconds. but by the time the page refreshes, textarea also comments on reloading. how to order textarea in the comments do not reload when the page refreshes? please help me !I want to create a social network website. but