To be truthfull mate, I think you just need to look here. So much depends on the scripting language that you use, but these tutorials are the best out there. Below is a example of the code needed to pull the values from a textbox in a form on a preceding page. It is written in Jscript.
I think you need to visit here: http://www.w3schools.com/asp/default.asp
Heres an example non the less.
var varusername = Request.Form("regusername");
var varpassword = Request.Form("password");