java - Problems with String Input

So, for some reason I'm having problems just USING a string input.

I don't know why. Maybe it's some incredibly stupid thing everyone knows, but I don't.

Here's the non-functioning code:

import javax.swing.*;


public class Thing {
public static void main(String[] args) {
    String input;

    JOptionPane.showMessageDialog(null,"Welcome to the test...");
    input = JOptionPane.showInputDialog("Do you wish to take the tutorial?" + "\n" +
                                        "If affirmative, enter 'Yes'");
    String i = input;


    if(i == "Yes") {
        tutorial();
    } else if(input=="'Yes'") {
        JOptionPane.showMessageDialog(null,"Don't actually put apostraphes around you're answer.");
        tutorial();
    } else {
        JOptionPane.showMessageDialog(null,"Remember, you can pull up the tutorial at any time with 'T'");
    }
}

Yes, I actually do have a tutorial method somewhere else, and it works fine.

The main problem is that if I enter 'Yes' or Yes, it still goes to the final else.

I only put in the

String i = input;

and changed it from

if(input == "Yes") {

because it didn't work then, either.

So what am I doing wrong?