Try:
tell application "Finder" to set fileNamez to name of theFile
if application "Evernote" is not running then
launch application "Evernote"
delay 3
end if
tell application "Evernote" to set matches to find notes fileNamez
if matches = {} then
tell application "Evernote" to set resultNote to create note from file theFile title fileNamez
tell application "SystemUIServer" to display dialog "no matches" buttons {"OK"}
end if