Auto-change Alfred Theme on DarkMode

set darktheme to "OS X Yosemite Dark Auto"
set lighttheme to "OS X Yosemite Auto"

tell application "System Events"
    set darkmode to (get dark mode of appearance preferences)

    if darkmode then
        set themename to darktheme
    else
        set themename to lighttheme
    end if
end tell

tell application "Alfred Preferences" to activate

tell application "System Events" to tell process "Alfred Preferences"
    tell window "Alfred Preferences"
        tell toolbar 1
            click button "Appearance"
        end tell
        tell tab group 1
            click radio button "Theme"

            repeat with aRow in row of table 1 of scroll area 1
                if value of first static text of aRow is themename then select aRow
            end repeat

        end tell

    end tell
end tell

tell application "Alfred Preferences" to quit