Random Record With SELECT TOP Does NOT Work

<%
Dim oConn, oRS, randNum
Randomize()
randNum = (CInt(1000 * Rnd) + 1) * -1
Set oConn=Server.CreateObject("ADODB.Connection")
Set oRS=Server.CreateObject("ADODB.recordset")
oConn.Provider="Microsoft.Jet.OLEDB.4.0"
oConn.Open Server.MapPath("temp.mdb")

oRS.Open "SELECT TOP 1 EMAIL_ADDRESS, r = Rnd(" & randNum & ") FROM TABLE1 ORDER BY r", oConn, adOpenStatic, adLockReadOnly

Response.Write oRS("EMAIL_ADDRESS")

oRS.close
oConn.close
Set oConn = nothing
Set oRS = nothing
%>

this gives the error: "No value given for one or more required parameters".

what i would really LOVE is for someone to fill in whatever required parameter im missing, but more important i would like to understand whats going on. there are people who go through life dumb and happy once something "works", but i need to understand how and why its working. even if this code did work, im confused with the SELECT statement (no, i dont have much SQL experience aside from basic queries). what is the "r = Rnd" line doing in the middle of the querie? how am i ordering by r?? also, i dont have an indexed, primary "ID" field in this databae. is that ok for this code to work?