To create a restaurant menu

Question

Dear all;

    I am designing a menu card for restaurant. I completed only one design form for SELECTING THE ITEM(eg:if i click the option drinks then the different kinds of drinks will be listed below). 

   In the same form if i click anyone of the drink then the price need to be displayed.

  If i give the quantity of the drink then the price should be displayed.

 Finally the total amount  should be added and displayed .

Kindly give me the codings for my above problem.

I will be very much thankfull to you..

 by,

Jesy