How do I set the record type in a Web-to-Lead form?

I have set up a Web-to-Lead form on our website, however the record type keeps defaulting to one record type, when I need it to be a different one. This is the html that I used to set the record type:

<input type=hidden name="recordType" value="01240000000ABCD">

Did I set this up incorrectly? I found this language somewhere online using Google.

Thanks for your help!

Chava