I am not overly experienced but I will try. I use formcalc for my
forms, this should work with slight adjustments:
On the button click event place the code
if (xfa.host.response("Password:", "Admin Password") == "password") then
form1.page2.presence = "visible"
endif
You cannot hide the page after it has been shown but this should work.
Let me know if these instructions are not clear enough.