I am having troubles with trying to retrieve a double variable that is already established outside the block and called inside but I want to return the value of the same variable so that I can apply it to a calculation.

the variable that I want returned is:

double quarter = 0;

but when I plug it into quarter in my first else/if statement, it plugs in 0 and not the value in my switch block. What can I do to retrieve the value?

        double quarter = 0;

        //Date entry will be calculated by how much KW user enters
        switch (input)
        {
            case "2/15/13":
                quarter = kwUsed * 0.10;
                break;
            case "4/15/13":
                quarter = kwUsed * 0.12;
                break;
            case "8/15/13":
                quarter = kwUsed * 0.15;
                break;
            case "11/15/13":
                quarter = kwUsed * 0.15;
                break;
            default:
                System.out.println("Invalid date");
        }


        //Declaring variables for calculations
        double base = 0;
        double over = 0;
        double excess = 0;

        double math1 = 0;
        double math2 = 0;


        //KW Calculations
        if (kwUsed <= 350)
        {
            base = quarter;

        }else if (kwUsed <= 500)
        {
            math1 = ((kwUsed - 350) * quarter);
            base = ((kwUsed * quarter) - math1);
            over = ((math1 * 0.1) + math1);

        }else if (kwUsed > 500)
        {
            math2 = ((kwUsed - 350) * 0.1);
            base = ((kwUsed * 0.1) - math2);
            math2 = ((kwUsed -350) - 50); 
            over = ((math2 * 0.1) + (15 * 0.1));
            double math3 =((kwUsed - 500) * 0.1);
            excess = ((math3 * 0.25) + math3);

        }

Edited to clarify question.