Sum of all even integers

"Use WHILE. Write an application that asks the user to input integers,
calculates the sum of all even integers, and displays the result.
Allow the user to decide when to quit."

So far this is what I have:
import java.util.Scanner;

public class Sum
{
    public static void main(String[] args)
    {
        // declare and initialize variables
        int count;
        double total, sum;
        String integer;

        count = 0;
        total = 0;
        String another = "y";

        Scanner in = new Scanner(System.in);

        // while the user inputs yes to continue
        while ((another.toUpperCase()).equals("Y"))
        {
            // Ask the user to input the integer
            System.out.println("Enter an integer: ");
            integer = in.next();

            // help!

            // check if the user wants to continue
            System.out.println("Would you like to enter another
integer (y/n): ");
            another = in.next();
        }

        // calculate the sum
        // help!

        // display the average
        System.out.println("The sum of all even integers is " + sum);
    }
}