How can I hide a field?

I've created a form with 3 conditional options. The conditions are based on a drop down at the top of the form. The issue I'm having is that each of those options is based on a category so in order to have the category assigned to the submitted post I had to also add category fields for each of the options. Now, I am trying to hide those additional category selections. I've tried targeting the selectors by adding:
li#field_1_22 {display:none !important;}
li#field_1_22 {display:none;}
#field_1_22 {display:none !important;}
#field_1_22 {display:none;}
But the fields are still showing up. Any hint would be greatly appreciated.

Sure. Here ya go http://www.eveek.com/form/ the last field before the submit button is what I need to hide yet still have it attached to the post.

Ya, I just realized that myself ;0)

This seemed to do it:
li#field_1_22 {display:none !important;}

Thanks for your time!