Navigating to form pages without changing address bar

Question

Hi,

 

I am creating a survey with multiple pages in it. When user clicks on Survey URL, internally its accessing different aspx page which has code for navigating to multiple pages of Survey. 

 

When user lands on 1st page the address bar shows parent page URL which is correct, as soon as user clicks on next button it shows URL of the page on which code is wriiten. I want to keep the parent page URL through out the surey. 

 

How do i achieve this?