title: Change input background color if the value of the input is valid in database
body: <p>The logic i am trying to do is:</p>
  
  <pre><code>input field starts white (Normal);
  after somebody finish typing, if the email does not exists, the input gets light red;
  if the email exists in the database, the input becomes white again;
  </code></pre>
  
  <p>I have my code like this:</p>
  
  <p>index.php</p>
  
  <pre><code>&lt;?php
  include 'my database connection page';
  include 'page that return me an array with all the emails';
  ?&gt;
  &lt;form method="POST"&gt;
      &lt;input type="text" name="email" id="email_field" onFocus="changeColorEmail(this)"&gt;
      &lt;input type="submit"&gt;
  &lt;/form&gt;
  </code></pre>
  
  <p>scripts.js</p>
  
  <pre><code>function changeColorEmail(which) {
      which.value = which.value.split(' ').join('')
          if (which.value == "&lt;? echo $user_data['user_email'] ?&gt;") {
              which.style.background = '#ffffff';
      }else {
              which.style.background = "#ffebe8";
      }
  }
  </code></pre>
  
  <p>Any ideas are appreciated!</p>
  
  <p><strong>user.php</strong> (contain a function that verify if the email exists in database)</p>
  
  <pre><code>function email_exists($email){
      return (mysql_result(mysql_query("SELECT COUNT(user_id) FROM user WHERE user_email = '$email'"), 0) == 1) ? true : false;
  }
  </code></pre>