Hook: comment_form

The comment for is named comment_form. As part of the core, this function has many hooks to customize the form’s contents.

We’re going to use a few of those hooks: comment_form_logged_in_after and comment_form_after_fields. They will add something after the “You’re logged in as…” message or the name, email and website fields respectively.

We’ll just call add_action for each of our hooks and in our hooked function spit out form code we want.

<?php

add_action(‘comment_form_logged_in_after’,‘pmg_comment_tut_fields’);

add_action(‘comment_form_after_fields’,‘pmg_comment_tut_fields’);

functionpmg_comment_tut_fields()

{

    ?>

    <pclass=“comment-form-title”>

        <label for=“pmg_comment_title”><?php_e(‘Title’);?></label>

        <input type=“text”name=“pmg_comment_title”id=“pmg_comment_title”/>

    </p>

    <?php

}

Depending on the them imstalled, the form can be beautified:

<?php

add_action(‘wp_head’,‘pmg_comment_tut_style_cheater’);

functionpmg_comment_tut_style_cheater()

{

    ?>

    <style type=”text/css”>

        #respond .comment-form-title {

            position:relative;

        }

        #respond .comment-form-title label {

            background:#EEE;

            -webkit-box-shadow:1px2px2pxrgba(204,204,204,0.8);

            -moz-box-shadow:1px2px2pxrgba(204,204,204,0.8);

            box-shadow:1px2px2pxrgba(204,204,204,0.8);

            color:#555;

            display:inline-block;

            font-size:13px;

            left:4px;

            min-width:60px;

            padding:4px10px;

            position:relative;

            top:40px;

            z-index:1;

        }

    </style>

    <?php

}

Source: PMG Adding extra fields to WordPress Comments