Here's my form:

<form action="<?php echo get_option('siteurl'); ?>/wp-comments-post.php" method="post" id="commentform" class="validate">  
   <?php if($user_ID) : ?>  
   <?php else : ?>
   <div class="label_container">
      <div class="left">
         <label for="author" class="label label_name">Name*</label>                 
      </div>
      <div class="right">
         <label for="email" class="label label_email">Email*</label>              
      </div>
      </div>
   <div class="input_container">
      <input id="name" name="author" class="required input_text input_name" type="text" value="" /> 
      <input id="email" name="email" class="required input_text email input_email" type="text" value="" />
   </div>         
   <?php endif; ?>
      <div class="label_container"> 
         <label for="comment" class="label label_comment">Comment</label>                 
      </div>
   <textarea id="comment_box" class="required input_comment" name="comment" cols="40" rows="6"></textarea>   
   <p><input name="submit" class="input_submit" type="submit" id="submit" tabindex="5" value="Submit Comment" />  
   <input type="hidden" name="comment_post_ID" value="<?php echo $id; ?>" /></p>  
   <input type="hidden" id="redirect_to" name="redirect_to" value="<?php echo get_bloginfo('wpurl');?>/comment">
   <?php do_action('comment_form', $post->ID); ?>  
</form>

I've needed fields on all inputs, but it's only focusing on the comment text area.

Any ideas?

if you would like client side validation then use

http://bassistance.de/jquery-plugins/jquery-plugin-validation/

and when you would like server side validation then use php

like

if(empty($_POST['email']))
{ 
  //show error msg
}else{
 //add comment
}

you are able to really control that in the settings discussion tab within the wp-admin panel.

make certain to check on Comment author must fill out name and e-mail. which should get it done.

is what you're searching for?