Dropdown required not working in codeigniter
<p>I want to make the mail is field required, but somehow its not working, am i missing something?</p>

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<pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;div class="col-md-5 "&gt;
  &lt;div class="control-group form-group"&gt;
    &lt;label class="control-label"&gt;
      Escalation Email Ids
    &lt;/label&gt;
    &lt;div class="controls"&gt;
      &lt;?php $options=a rray(); if(count($useridsoptions)){ foreach($useridsoptions as $key=&gt;$val){ $options[$key]=$val; } } echo form_dropdown('esc_users[]', $options, explode(",",$row-&gt;esc_users),'id="esc_users" class="form-control function col-md-12 select2", reqired="required" multiple'); ?&gt;
    &lt;/div&gt;
  &lt;/div&gt;
&lt;/div&gt;</code></pre>
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