Calculate With Buttons

Hi,

I’m creating a calculator of sorts which gives the user options, if the options are chosen it will add the number to two dynamic fields. Here is the actionscript…

[SIZE=1][COLOR=Blue]totalPrice=“599000”;
featurePrice= “0”;

total_txt= totalPrice;
features= featurePrice;

function addGarage1(){
features=Number (featurePrice)+ Number (23000);
total_txt=Number (totalPrice)+ Number (23000);
featuredPrice = features;
totalPrice = total_txt;
}
function minusGarage1(){
features=Number (featurePrice)- Number (23000);
total_txt=Number (totalPrice)- Number (23000);
}
function addGarage2(){
features=Number (featurePrice)+ Number (23000);
total_txt=Number (totalPrice)+ Number (23000);
}
function minusGarage2(){
features=Number (featurePrice)- Number (25000);
total_txt=Number (totalPrice)- Number (25000);
}
[/COLOR][/SIZE]
Each button is calling these functions when they are pressed, and it adds to these numbers in the dynamic text field, however when they subtract they are subtracting from the original number that I have defined at the top and not the number added. What I want to do is update the number after each function but I do not know where to begin. I was wondering if anyone out there can help me out.