Rule to add the word money in ticket

Hello! I created a tag called ticket money then when you click on the tag values change appears to take example 10, 20, 50 100, these values make a calculation with the formulate [= F (TN ('{TICKET TAG:MONEY}') - (TN ('{TICKET TOTAL}'))) so that when the customer informs the value of the ticket value appears the motorcyclist should take, I have 2 problems when first needed to pick up the tag-money appears if the phrase PAYMENT MONEY and also created the tag CARD ticket when one chooses this option that does not appear to the change in formula if I put [<J10>VALUE OF CHANGE:    | [= F (TN ('{TICKET TAG:MONEY}') - (TN ('{TICKET TOTAL}')))] ] (note the brackets at the beginning and at the end) when not used to hide is not hiding