Forms Data Controls :: Maintain Page State On Postback From Other Webpages?

I have a abc.aspx page having some control like (drop downs, text boxes), i am filling a grid based on selected items in the drop downs and date selected from the ajax calender extender control attached to the from data and to date text boxes.

Inside grid there is a link which redirects to bcd.aspx, this page (bcd.aspx) is having a back button to redirect abc.aspx.

Now what i want is, abc.aspx should main its state like grid, drop downs and text boxes should be shown as it was earlier, i.e. all should have same values as it was at the time of redirecting to bcd.aspx.

Yes, there is a way to maintain the state by passing all values from query string and than get all values back and rebind all controls. But i don't want to go this way because i will have pass so many values in query string.