landing page form inquiry

[Anonymous]

I have currenlty have a landing page form and I would like to know who to setup a flow/triggered for the following condition.

1. IF on Whitelist THEN user instantly recieved email allowed to download content.
   1. After a user registers and is approved, users should not need to re-register to receive content.

[Anonymous]

One option is a JavaScript to evaluate whether _mkt_trk is defined and then query the database through SOAP API getLead.

http://developers.marketo.com/documentation/soap/getlead/

[Anonymous]

I also hear people discuss using a custom segment for this same thing.