Passing variables between pages

Hi,

I'm trying to pass some variables that requires users to register. The first page, users key in the necessary information. After which, the 2nd page will load and display the infomation that the user had keyed-in previously, from this page the user can choose to confirm or cancel. On confirmation, the 3rd page will load and that should be when the information is inserted into the database. My problem is when it reaches the 3rd page, the values seem to be gone, as the page loads with an error stating something like my user_id is not present(being a primary key, it cant be null). In the 2nd page, when i was trying to show the info, i added some hidden inputs at the bottom, its something like

<input id="user_id" type="hidden" value="<%=user_id%>">

and so on, i was expecting these inputs to be passed over to the 3rd page, but it doesnt seem to be this way, anyone can help me on this?May be you can try to use session variable.