I would suggest that you us the Craft Member Registration form and have them register as actual Craft members.
Once they're members and logged in, you can display elements of a page using something like:
{% if currentUser %}
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{% endif %}
More info on the above, here: How can I determine if a user is logged in, and who that user is?
An obvious benefit to the above is that a member would only need to log in once and gain access to relevant content, instead of being asked to submit the information each time.
Let us know how you get on.