Referring a Webform type from other webform

Hi there:
Suppose I have two webforms, the first is defined as:
Public partial class webform1 : System.Web.UI.Page
{ ... }
and the second as
public partial class webform2: System.Web.UI.Page.
{...}
When I make a reference from webform2 to webform1, such as
If (PreviousPage is webform1) {
}
I get an error, it says that webform1 doesn't exist.
Aren't all public webforms really public?
...