Requiring Info before user can view pages

I'm trying to figure out how to write a webpage so that it requires a visitor to enter contact info like a name and phone and email before they are allowed in to view certain pages. I dont want it to be that they are required to create a username and password but just that a visitor has to provide some contact info that can be emailed to us before they are allowed in to view certain pages??? Any help

this really should be in the javascript forum, but I am assuming you would use a javascript prompt() command on an onload event

Javascript can be disabled. Using a server side script and a form that makes a cookie or session on successful submit. Then check for the session on each page or put their name in a database and have them put their name and email in each time.