how to sustain value of a control when moving from one page to another

Question

This is fine with the same page. But I have 2 Pages. Page A: Contains the following controls: Select Group Button Listbox control Radiobutton list control Search Button Page B: Contains the Following controls: Treeview control with the different nodes Now, my issue is this when I Clicks on the select a group button and sleect a node from the tree of PAge B it works fine. But when I select a node form PAge B and it shows me in Listcontrol of PAge A and then I select a radio button option and then Again select a Group and then press ok Button of PAge B it redirects me at the PAge A but my previous value is not here. and at this time I am with newly selected value. below is a skectch what is going on: Page A-----> Select Groups-------->PageB(Tree Control) --------------> Select Node ------------Press Ok Button----------->Redirects to PAge A----------> Shows the selected node value in Listbox control. ( this is Ok, it is working like this) But problem lies here : Page A-----> Select Groups-------->PageB(Tree Control) --------------> Select Node ------------Press Ok Button----------->Redirects to PAge A----------> Shows the selected node value in Listbox control ------------->Then select a RadioButton option ------------->press Select Groups Button -------------> Redirects to the PAge B-------------->PageB(Tree Control) --------------> Select Node ------------Press Ok Button----------->Redirects to PAge A----------> But at this time my previously selected value is not here and only one criteria will be added up here. Please sort out this issue Thanks, junior