Changing the fields I see in when I view an individual reference

I’ve used EndNote X without customizing it since I upgraded to it, but I’m now ready to get rid of all the superfluous fields that I don’t use.  

This doesn’t work:  

I open the preference window, click on “reference types” and then click on the “modify reference types” button.  I then go through and (with “Journal Article” at the top, for example) select things from the right hand column like “short title” and “url” and erase them (highlight, then delete).  I close that window, click “Save” and close the preference window.   [after this process, “short title” and “url” are still part of the view when I open up an old or new reference.

What will work?

Chris Hill

Mac OS 10.5.4

Endnote X (Bld 1885)