cfif with or problem

hi

i'm trying to use multiple expressions in a cfif

ex:

<cfif (Evaluate(test.itemcode) is not "HDMI") OR (Evaluate(itemcode) is not "DVI")>

this should result in returning everything that 's not with hdmi or dvi , right? it doesn't , it returns everything including them

but when I do:

<cfif (Evaluate(test.itemcode) is not "HDMI")>

it excludes the hdmi from the list...

what am I doing wrong?