include (classic asp) in asp.net VB?

Hi,
In classic asp I had several files I had to include into others.
How do I do this in asp.net (VB)?
e.g.:
<!-- #include file="301.asp" --> <!-- #include file="var.asp" --> <!-- #include file="meta.asp" -->
If I got it right the code behind file is some kind of such include, but what if I have subs and functions in other files I would like to use in other files too?

Thx in advance,
Pascal
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