I need a manual on this scale so I can use it. It is glass top has two arrows on right side - arrow up and arrow down, On the left side two buttons - set and user. I have no idea how to use any of the buttons. I got this at a flea market and there were no instructions / manual. Please send me manual - my email addy is harwooddoll@comcast.net Thanking you in advance Doris Beales