Since HTTP is a stateless protocol, the server does not know anything 
about previous requests. Passing values to the server therefore has to be 
done via state management mechanisms.

Common ways to maintain state are:

*Querystring:

javascript:
  document.location.href = "/root/somefile.asp?Variable=" + JSvar
vbscript in /root/somefile.asp:
  VBSvar = Request.Querystring("Variable")

*Or a hidden form-field (POST):

javascript:
  document.form.action = "/root/somefile.asp"
  document.form.hiddenformfield.value = JSvar
  document.form.submit()
vbscript in /root/somefile.asp:
  VBSvar = Request.Form("hiddenformfield")