Code pulling info from AD brings in users and objects in several different OUs, how to filter out objects

Apologies for the mess my code is...

I'm using code to generate an employee directory from AD. It's quite simple, but my AD has users and objects in different OU's. I want to run an if that says something like "if sn is null, loop" but I know I'm not quite putting in the syntax properly.

Should I have the sql statement filter out that info or in the code when running the loop? Current sql statement is "select givenName,sn,title,mail,telephonenumber,mobile,sAMAccountName FROM '"+ usersOU +"' where sAMAccountname='*' ORDER by sAMAccountname" I'm finding that SN and title are the empty AD attributes.

    <h1>Company Directory</h1>

        <%
        ' Define the AD OU that contains our users
        usersOU = "LDAP://OU=xxx,DC=xxx,DC=com"    
        ' Make AD connection and run query
        Set objCon = Server.CreateObject("ADODB.Connection")
        objCon.provider ="ADsDSOObject"
        objCon.Properties("User ID") = "xxx"
        objCon.Properties("Password") = "xxx"
        objCon.Properties("Encrypt Password") = TRUE
        objCon.open "Active Directory Provider"
        Set objCom = CreateObject("ADODB.Command")
        Set objCom.ActiveConnection = objCon
        objCom.CommandText ="select givenName,sn,title,mail,telephonenumber,mobile,sAMAccountName FROM '"+ usersOU +"' where sAMAccountname='*' ORDER by sAMAccountname"
        Set objRS = objCom.Execute
        ' Loop over returned recordset and output HTML
        Response.Write "<table border=1>" + vbCrLf
            Do While Not objRS.EOF Or objRS.BOF
                    Response.Write "  <tr>"
                        Response.Write "<td>" + objRS("givenName") +  " " 
                        + objRS("sn") + "<br>" + objRS("title") + "<br>" 
                        + objRS("sAMAccountName") + "</td>"
                        Response.Write "<td>" + objRS("mail") + "<br>"
                        Response.Write  + objRS("telephonenumber") + " 
                        <br>"
                        Response.Write  + objRS("mobile") + "</td>"
                        Response.Write "</tr>" + vbCrLf
                        objRS.MoveNext
                        Response.Flush

            Loop
        Response.Write "</table>"
        ' Clean up
        objRS.Close
        objCon.Close
        Set objRS = Nothing
        Set objCon = Nothing
        Set objCom = Nothing
        %>

I want a list of only humans with name, title, email, phone number, mobile number. I don't want any DL's or computers from AD.