Java: if statement with not equals breaking the program : <p>I can't figure out why my code isn't working. </p>

<p>It appears to be breaking around the if not equal to yes or no area.</p>

<p>Here's my code:</p>

<pre><code>public static void main(String[] args) {
    // TODO code application logic here

    Scanner user_input = new Scanner(System.in);

    String name;
    System.out.println("Hello, what is your name?");
    name = user_input.next();

    System.out.println("");

    String name_answer;
    System.out.println("Your name is " + name + ". Is this correct? (yes/no)");
    name_answer = user_input.next();

    System.out.println("");

    if (!name_answer.equals("yes" + "no")) { 
        System.out.println("Answer not valid. Please input again.");
        name_answer = user_input.next();
        while (!name_answer.equals("yes" + "no")) {
            System.out.println("Answer not valid. Please input again.");
            name_answer = user_input.next(); } }

    if (name_answer.equals("yes")) {
        System.out.println("Thank you, " + name + ". Please proceed to the next question.");
    } else if (name_answer.equals("no")) {
        System.out.println("Please reinput your name correctly.");
        while (name_answer.equals("no")) {
            String name_again;
            System.out.println("");
            System.out.println("What is your correct name?");
            name_again = user_input.next();

            System.out.println("");

            System.out.println("Your name is " + name_again + ". Is this correct? (yes/no)");
            name_answer = user_input.next();  }
</code></pre>

<p>If i comment out the not-equals block of code (displayed below), the program works. However, with the block of code in, the program breaks. </p>

<pre><code>    if (!name_answer.equals("yes" + "no")) { 
        System.out.println("Answer not valid. Please input again.");
        name_answer = user_input.next();
        while (!name_answer.equals("yes" + "no")) {
            System.out.println("Answer not valid. Please input again.");
            name_answer = user_input.next(); } }
</code></pre>

<p>My goal is to have any answer not equal to "yes" or "no" be reinputted while a "yes" or "no" brings the program to another step. Thanks for the help.</p>
