Here's a nice, simple way to pass values from one page to another:
'Add data to the context object before transferring
Context.Items("myParameter") = x
Then, in WebForm2.aspx:
'Grab data from the context property
Dim x as Integer = CType(Context.Items("myParameter"),Integer)
Of course there are a number of ways to pass values from one page to
another, such as using the querystring, cookies, session,
context, saving to a temporary table in the database between each page, etc.
You'll have to decide which technique is best for your application.
Here are several good articles on the subject to help you ...