Getting a value from an input text box

i have an imput text box, with a var of dimes…
lets say the user entered 9, then pressed total…
i want the total, to give the value of 9 dimes, wich is .90

what i tried was something like this:

tDimes = dimes * .10;

tButton.onPress = function() { = "total: " + tDimes;

but as an output i get 0 :frowning: