title: form validation on codeigniter if the value is empty and below 100
body: <p>How to validate my form on codeigniter, if the value is empty and below 100.</p>
  
  <p><strong>this is my controller</strong></p>
  
  <pre><code>function aksi_deposit(){
      if ((empty($_POST['deposit']))&amp;&amp; (($_POST['deposit'])&lt;100)) {
          redirect('deposit');
      } else {
          $whc = $this-&gt;input-&gt;post('deposit');
          $money = $whc * 8000;
          $idUser= 1;
          $b['data'] = $this-&gt;m_user-&gt;tampil_invoice($idUser);
          $b['coin'] = $money;
          $b['whc'] = $whc;
          $this-&gt;load-&gt;view('user/v_invoice',$b);
      }
  }
  </code></pre>