I want to decrease textbox value by 0,15 every second with timer tick.

Question

I want to decrease textbox value by 0,15 every second with timer tick. i use c# net framework

for examle textbox1 value is 10000 and textbox2 value = 0,15

so i want every second textbox1 to be ( 10000 , 9.999,85 , 9.999,7 .......0)

thanks in advance!