title: Use image as radio button on Contact Form 7
body: <p>I'm trying to create an option for people to select an image in a WP CF7 form. As they will only be able to select one option, it seems to me that using a radio button function is the best way to go. I found an example of a code on <a href="https://wpquestions.com/Need_Image_as_a_Radio_Button_in_Contact_Form_7/19618#answer_16362" rel="nofollow noreferrer">https://wpquestions.com/Need_Image_as_a_Radio_Button_in_Contact_Form_7/19618#answer_16362</a> but adding the code does a) not create a tag in the admin section, and b) only returns the full shortcode on the page, instead of returning the desired images.</p>
  
  <p>I did find this <a href="https://stackoverflow.com/questions/42792051/how-to-make-custom-form-tag-in-contact-form-7-required">How to make custom form-tag in contact form 7 required</a> here on this forum. I tried adding the </p>
  
  <pre><code>add_action( 'wpcf7_init', 'wpcf7_add_form_tag_imageradio' );
  </code></pre>
  
  <p>But it returned the following error:</p>
  
  <blockquote>
    <p>Warning: call_user_func_array() expects parameter 1 to be a valid callback, function 'wpcf7_add_form_tag_imageradio' not found or invalid function name in /home2/clay/public_html/wp-includes/class-wp-hook.php on line 298</p>
  </blockquote>
  
  <p>Any ideas on how to solve this?
  Theme used is OnePage Express</p>