Why am I getting this VBScript "Overflow" error?

Question

Intermittently I am getting "VBScript runtime error '800a0006': Overflow" on this line:

Response.Cookies("AffiliateID").Expires = Date() + 30 '30 day cookie

The error message is referencing this line but maybe it is happening in the code around it, which follows:

 elseif Session("LoggedIn")<>1 and not isEmpty(request.querystring("aff")) then
    Dim arr_service_area_options, c
    arr_service_area_options = Split(Application("SERVICE_AREA_OPTIONS"),",")
    for c = 0 to UBound(arr_service_area_options)
        if CInt(Trim(request.querystring("aff"))) = CInt(Trim(arr_service_area_options(c))) then
            Session("AffiliateID") = arr_service_area_options(c)
            Response.Cookies("AffiliateID") = arr_service_area_options(c)
            Response.Cookies("AffiliateID").Expires = Date() + 30 '30 day cookie                    
            exit for
        end if
    next

Answer 1

Check for any code that could throw a Divide by Zero error nearby