title: URL to PHP file not working
body: <p>I'm trying to learn HTML and PHP so trying to build a login form with some links. </p>
  
  <p>The bebsite opens OK, however the link to sign up seems to be going nowhere. </p>
  
  <p>My index file as follows:</p>
  
  <pre><code>&lt;?php
   include ('../app/header.php');
   ?&gt;
      &lt;section class="main-container"&gt;
        &lt;div class="main-wrapper"&gt;
          &lt;h2&gt;Home&lt;/h2&gt;
        &lt;/div&gt;
       &lt;/section&gt;
   &lt;?php
     include ('../app/footer.php');
   ?&gt;
  </code></pre>
  
  <p>And my header php as follows:</p>
  
  <pre><code>&lt;!DOCTYPE html&gt;
  &lt;html lang="en" dir="ltr"&gt;
   &lt;head&gt;
    &lt;meta charset="utf-8"&gt;
    &lt;title&gt;Welcome&lt;/title&gt;
     &lt;link rel="stylesheet" type="text/css" href="/css/styles.css"&gt;
   &lt;/head&gt;
   &lt;body&gt;
  &lt;header&gt;
    &lt;nav&gt;
      &lt;div class="main-wrapper"&gt;
        &lt;ul&gt;
          &lt;li&gt;&lt;a href="/index.php"&gt;Home&lt;/a&gt;&lt;/li&gt;
        &lt;/ul&gt;
        &lt;div class="nav-login"&gt;
          &lt;form&gt;
            &lt;input type="text" name="uid" placeholder="Username\e-mail"&gt;
            &lt;input type="password" name="pwd" placeholder="password"&gt;
            &lt;button type="submit" name="submit"&gt;Login&lt;/button&gt;
          &lt;/form&gt;
          &lt;a href="../app/signup.php"&gt;Sign up&lt;/a&gt;
        &lt;/div&gt;
      &lt;/div&gt;
    &lt;/nav&gt;
  &lt;/header&gt;
  </code></pre>
  
  <p>The issue is that <code>href</code> link to signup php takes me nowhere. However if I copy the files into public directory and change the path in the link it then works fine. </p>
  
  <p>Also, after clicking signup link, my URL shows localhost\app\signup.php. </p>
  
  <p>Im using <strong>xammp</strong>. </p>
  
  <p>Could someone advise as to why the link does not work as expected? </p>
  
  <p>Thanks</p>
  
  <p>UPDATED:</p>
  
  <p>My directory is as follows: </p>
  
  <p>C:\xampp\htdocs\basicwebsite\public\index.php</p>
  
  <p>and all PHP files are here: </p>
  
  <p>C:\xampp\htdocs\basicwebsite\app</p>