如何通过单击浏览器的后退按钮获得相同的页面

i am using asp.net with c# in my aspx page i have an update panel in this panel i have some links to other sites, which is open on the same window. after clicking on these links me when i am getting back through browser's back button i am not getting the same results on the update panel...i am using asp.net with c# in my aspx page i ha