how to display only two digit of number behind decimal point in textbox?

hello,

i've made some calculation form and the idea is to display the result in textbox, but when the program has finish calculating it, my textbox by default display ith long number like 23,54683248. i use double data type for my program

my question is, how to display only two digit of number behind decimal point in my textbox? so the textbox will display 23,54

thanks before