title: 4 Buttons to different sites but with 1 entered usercode on the end of each url
body: <p>I am looking to have a page with a user entered code then a choose of 4 url buttons. When user enters code and selects a button. The code will open a new window to the website on the button (site1, site2, site3, site4) and add the usercode onto the end of the url.
  I have managed to do it for one site with the below code</p>
  
  <pre><code>&lt;html&gt;
  &lt;head&gt;
  &lt;title&gt;User Button Test June 2018&lt;/title&gt;
  &lt;meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1"&gt;
  &lt;/head&gt;
  
  &lt;body bgcolor="#FFFFFF" text="#000000"&gt;
  
  &lt;form action="username.php" method="post"&gt;
  
  &lt;p&gt;&lt;label for="user-name"&gt;Please enter your user code&lt;/label&gt;&lt;input type="text" name="user-name" id="user-name" /&gt;&lt;/p&gt;
  
  &lt;p&gt;&lt;input type="submit" id="submit" class="button" value="Site 1" /&gt;&lt;/p&gt;
  &lt;br&gt;
  
  &lt;/form&gt;
  &lt;/body&gt;
  &lt;/html&gt;
  
  
  php file (username.php)
  
  &lt;?php
  
      if (isset($_POST["user-name"])) {
  
  
          $username = $_POST["user-name"];
  
  
          $url = "http://site1.mysites.co.uk/?strata=$username";
  
          header( "Location: $url" ) ;
  
      } else {
  
          // do nothing
  
      }
  
  ?&gt;
  </code></pre>
  
  <p>Struggling to find a way to do 4 and was wondering if anyone has achieved similar ?</p>