how do i reprogram sales tax rate to PLU keys ER-5240M SAM4S i cleared the

[noor]

memory grand totals and PLU files ,? i cleared the memory grand totals and PLU files , then i programed the sales tax rate at 08.75000 and pressed tax 1 shift. arter this setup i went back to the regular registar when i pressed the PLU keys it shows the sales price without the sales tax amount when i hit the subtotal key.