WPF-Radio button and checkbox validation using if statements

Question

Hi i am quite new to programming so the syntax  is still very confusing for me.

My problem is I want to add an option when the user checks radio button(warranty) (adding 10% to the subAmount using an if statement.

I am using...

 

if (threeYearRadioButton.IsChecked == true)

{

threeYearRadioButton = threeYearWarranty;

}

 

threeYearRadioButton(is the name of the radio button in my xaml code)

double threeYearWarranty = 0.1d; (is the name i have used to define in my cs code)

 

If the user checks one year there is no charge on top of the subAmount.

If three years is selected then 10% is added on top of the SubAmount and

five years = 20% added on top of the subAmount.

 

 I am having the same issue with checkboxes:

If the user checks "totalWindowTinting", then $150 is added to the subAmount.        int totalWindowTinting = 150;

If the user does not check the window tinting box then there will be no additional price added to the SubAmount.

 

I know i need to use an if statement, but it just comes up with errors wen i  start using the ISChecked property.

 

please help!

 

 

 

Thanks,

 

James