title: Disable the submit button if no radio button is clicked
body: <pre><code>&lt;tr&gt;
      &lt;td height="250px" width="300px"&gt;&lt;center&gt;&lt;label&gt;&lt;input type="radio" name="carrier" &lt;?php if (isset($carrier) &amp;&amp; $carrier=="LBC") echo "checked";?&gt;  value="LBC"&gt;&lt;img src="../paymentoptions/lbc.png" alt="LBC" class="picture" width="245px" style="margin:10px"/&gt;&lt;/label&gt;&lt;/td&gt;
  
      &lt;td height="250px" width="300px"&gt;&lt;center&gt;&lt;label&gt;&lt;input type="radio" name="carrier" &lt;?php if (isset($carrier) &amp;&amp; $carrier=="PickUp") echo "checked";?&gt;  value="PickUp"&gt;&lt;img src="../paymentoptions/pickup.jpg" alt="Pick-Up" class="picture" height="210px" width="250px" style="margin:10px"/&gt;&lt;/label&gt;&lt;/td&gt;
  &lt;/tr&gt;
  </code></pre>
  
  <p>Hello, How do i disable my form submit button if no option is chosen? thank you</p>