how to build subpage with the same header.php? : <p><strong>my goal:</strong>  is when i click the sign up link it will move me to the signup.php and it will show the page!</p>

<p>i am trying to build asub page with the same login form header with php, 
 but when i start using the</p>

<pre><code> &lt;?php
include_once 'header.php';

?&gt;
</code></pre>

<p>it dosent work and it dosent move me to the subapge!</p>

<p>here is the code : </p>

<p><strong>index.php</strong></p>

<pre><code>&lt;?php
include_once 'header.php';

?&gt;

&lt;section class="main-container"&gt;

&lt;div class="main-warrper"&gt;

&lt;h2&gt; signup &lt;/h2&gt; 
&lt;/div&gt;

 &lt;/section&gt;

&lt;?php
include_once 'footer.php';

?&gt;
</code></pre>

<p><strong>header.php</strong></p>

<pre><code>&lt;!DOCTYPE html&gt;
&lt;html&gt;
&lt;head&gt; 
&lt;title&gt; login form &lt;/title&gt; 
&lt;link rel="stylesheet" type="text/css" href="style22.css"&gt;

&lt;/head&gt; 

&lt;body&gt; 

&lt;header&gt;

&lt;nav&gt;

&lt;div class= "main-warrper"&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="email"&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="signup.php"&gt;sign up &lt;/a&gt; 
&lt;/div&gt;

&lt;/div&gt;
 &lt;/nav&gt; 

&lt;/header&gt; 
</code></pre>

<p><strong>signup.php</strong></p>

<pre><code>&lt;?php
include_once 'header.php';

?&gt;

&lt;section class="main-container"&gt;

&lt;div class="main-warrper"&gt;

&lt;h2&gt; signup &lt;/h2&gt; 
&lt;/div&gt;

 &lt;/section&gt;

&lt;?php
include_once 'footer.php';

?&gt;
</code></pre>
