i can not identify the mistake in my code : <p>// i dont know where is the problem here </p>

<p>package javaapplication3;
import java.util.Scanner;</p>

<p>public class JavaApplication3 
{</p>

<pre><code>public static void main(String[] args) 
{
    Scanner keyboard=new Scanner(System.in);
    int num1,num2;
    String input;
    input= new String();
    char again;
    while (again =='y' || again =='Y')
    {
        System.out.print("enter a number:");
        num1=keyboard.nextInt();
        System.out.print("enter another number:");
        num2=keyboard.nextInt();
        System.out.println("their sum is "+ (num1 + num2));
        System.out.println("do you want to do this again?");
    }

}
</code></pre>
