The standard flow of the site is this one: User enters main page, navigates to detail page and depending on his inputs, he goes into the conditional page, then returns to the detail page.

What I am wondering is how you set the system so that, if a user who got into the conditional page presses back, he returns to the previous page, the detail page. However, if the user presses back after the conditional page he should go back to the one before the detail page, the main one, rather than the actual previous page he was in, the conditional.

Basically, a way to make you able to navigate back from one page but not to navigate back to it.