sb4short

How do I get the following contact form to work:

<form action="contact_form.php" method="post">

<div class="tm-contact-form">

<div class="form-group">

<input type="text" id="contact_name" class="form-control" placeholder="Name..." />

</div>

<div class="form-group">

<input type="email" id="contact_email" class="form-control" placeholder="Email..." />

</div>

<div class="form-group">

<input type="text" id="contact_subject" class="form-control" placeholder="Subject..." />

</div>

<div class="form-group">

<textarea id="contact_message" class="form-control" rows="8" placeholder="Message..."></textarea>

</div>

</div>

<button type="submit" class="btn text-uppercase templatemo-btn templatemo-send-btn">Send</button>

</form>