Change the font of all text boxes in a Powerpoint presentation

ppt-font-change.scpt

tell application "Microsoft PowerPoint"
    tell active presentation
        set theSlideCount to count slides
        repeat with a from 1 to theSlideCount
            set numShapes to count shapes in slide a
            repeat with b from 1 to numShapes
                set sh to (shape b of slide a)
                if has text frame of sh then
                    set f to font of text range of text frame of sh
                    set font name of f to "Arial"
                    set east asian name of f to "MS Gothic"
                end if
            end repeat
        end repeat
    end tell
end tell