"The Young Salesman" joke

A proprietor very keen on obtaining the maximum from the customer, had drilled his
sales staff not to turn away any customer, but to try to entice them with a similar option -
like he said - if they require rose brand sugar and we don't have the stocks offer them
elephant brand sugar etc etc.
Well a nervous young salesman eager to show off how effective a job he could do, met his first customer that day - an old lady who hobbled in. He greeted her with a cherry good morning and she stated that she required toilet paper.( A luxury which was not freely available or well known during this period.)
The salesman said sadly "Mam I am sorry I cannot give you toilet paper as we have run
out of stocks, but could I offer you instead a good quality tissue paper?"
The old lady thinking the man was trying to be fresh gave him a nasty look and
said No No thank you.
The salesman not wanting to be beaten then offered her some carbon paper - in colours blue or black. The old lady gave him a withering look and rudely said No.. No. ..
Getting into the spirit of the thing and somehow wanting to make a sale, he offered her as a last resort --- Mam can I give you some sand paper.!
(I don't have to tell you how it all ended. ..)