Your Passpack It! button can only autofill two fields for you. If you come across a login form with three fields (for example, Company, User ID and Password), then try one of these two options.
1. Autofill + Paste
Manually type or paste in one of the fields, then you can train Passpack to auto-fill the other two for you. Keep in mind this will only work when all three fields are present on the same page.
2. Copy/Paste all Three
Double click on your Passpack It! button. In the window that pops up, click on the copy/paste tab. If you've stored the Company name in the notes section of your entry, then you can simply copy and paste all the info directly into the login form.