Numbers Instead Of Text

I'm using the follwoing code to retrieve some values from an Access database:

<%
Dim PageStr
PageStr=Request.Querystring("PageStr")
SQL="SELECT * FROM images WHERE page = '" & Replace(PageStr, "'", "''") & "'"
set conn = server.createobject("ADODB.Connection")
conn.open "ContentDBase"
set img=conn.execute(SQL)
%>

This works fine. However, I want to change the 'page' field from a string to a number (i want to filter by the primary key rather than the description), but using the existing code I'm told I have a 'type mismatch' or something. I'm guessing I need to modify the code slightly to deal witha number field as opposed to a text field?