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If you want a box to display where you have to enter a code, this is the field you use. I have no clue how it works, you will have to look in the source code.
box_money
The amount of money the player has to pay for the selected option, appears in the confirmation box as amount of gold, silver, copper.
The DB value you insert here must be given in the number of copper, so 10 gold is entered as 100000 (10g 00s 00c).
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