Fast pay menu script (restricted to menu only)

This is very handy script to make sure nobody can pay anything else than what you ask for certain product. For default it will give only 1 option for price and disable possibility of paying custom price. Can be used with vendor or tip jar scripts. Very good combination with my
1 item, 1 prim vendor script for excample.

(remeber to set the prim you are going to use this script. as pay item for default.)