Error when leaving input blank in ASP

Question

I am developing a script to allow users to write to Active Directory. The problem is that, when I leave a field blank, it results in an error. When, however, I put a value in, even a space, it seems happy. I have the following code:

 <%@LANGUAGE="VBScript">
%>
<%
if isEmpty(request.form("subval")) then

response.write("You did not submit the form, please <a href='ldap.asp'>go back</a>")

else
'If the subval field is empty, we know the form has been submitted OK
dim firstname, lastname, email, telephonenumber, mobile, description
ADUser = "LDAP://OU=Staff,OU=Users,DC=example,DC=internal"
' Make AD connection and run query

subval = request.querystring("account_name")
'This value held the CN earlier, it is now overwriten here

Set objCon = Server.CreateObject("ADODB.Connection")
objCon.provider ="ADsDSOObject"
objCon.Properties("User ID") = "EXAMPLE\Exampe"
objCon.Properties("Password") = "TestPassword"
objCon.Properties("Encrypt Password") = TRUE
objCon.open "Active Directory Provider"

Set objCom = CreateObject("ADODB.Command")
Set objCom.ActiveConnection = objCon
objCom.CommandText ="select sAMAccountName, distinguishedName FROM '"+ ADUser +"' where sAMAccountname='"& subval &"'"
Set objRS = objCom.Execute
distinguishedName = objRS.Fields("distinguishedName")    
objRS.Close
objCon.Close
Set objRS = Nothing
Set objCom = Nothing
'We select the distinguishedName from AD

firstname = request.form("firstname")
lastname = request.form("lastname")
email = request.form("email")
telephonenumber = request.form("telephonenumber")
mobile = request.form("mobile")
description = request.form("description")
Const ADS_PROPERTY_UPDATE = 2 

Set objUser = GetObject _  ("LDAP://" & distinguishedName) 
if (IsNull(firstname)) Then
    firstname = "  "
end if

if (IsNull(lastname)) Then
    lastname = "  "
end if

if (IsNull(email)) Then
    email = "  "
end if

if (IsNull(telephonenumber)) Then
    telephonenumber = "  "
end if

if (IsNull(mobile)) Then
    mobile = "  "
end if

if (IsNull(description)) Then
    description = "  "
end if

   objUser.Put "givenName", firstname
   objUser.Put "mail", email
   objUser.Put "sn", lastname
   objUser.Put "mobile", mobile
   objUser.Put "description", description
   objUser.Put "telephoneNumber", telephonenumber
   objUser.SetInfo
   Response.Write("User data for "& subval &" has been modified")
   end if
%>

The error I get whenever I leave a field blank is why I am trying to inject spaces into the variables since that seems to work in my form.

The error I get is on the SetInfo line

error '8007200b' /updateldap.asp, line 68

I'm not sure what I can try since I've done all the stuff I can think of

Answer 1

8007200b = LDAP_INVALID_SYNTAX (The attribute syntax specified to the directory service is invalid)

I would say that you have worked out what the issue is. LDAP attributes cannot be NULL. You probably don't even need to have spaces, an empty string might work as well.

e.g.

if (IsNull(firstname)) Then
    firstname = ""
end if