get the value of checkboxes

yes. You are going to need to send form values over, you have many options in fact, you can send it over in a hidden input, temporarily store it in a database, use the asp.net viewstate (ugh), keep all of your stuff on one page, but swap out the elements using tfe visisble attribute to acheive the functionality of two pages then it will all be still there to the server but not in your markup, but perhaps your best solution would be the good old query string.