I have a class,I want to read the cookies with the class code,The class haven't the aspx pages.
The class code like this:

class HDLab
    dim membername

    public sub new()
        if not (context.Request.Cookies("HDLab") is nothing) then
           membername=context.request.cookies("HDLab")("membe rname")
        end if
    end sub
end class

when I run the code,It's have this errors:
System.NullReferenceException

'Nothing' is not the same as 'DBNull'. Try changing your if statement to this:

if not (context.Request.Cookies("HDLab") is System.DBNull.Value) then...

If you are using code behind you also have to add 'Imports System.DBNull' to the top of your code.

Even if you call its full path, "System.DBNull", you still have to import it?