the original contact form includes spry validation code at the bottom.
the error in dreamweaver is accuirng because you have not copied that code:
<script type="text/javascript">
<!--
var sprytextfield1 = new Spry.Widget.ValidationTextField("sprytextfield1", "none", {validateOn:["blur"]});
var sprytextfield2 = new Spry.Widget.ValidationTextField("sprytextfield2", "email", {validateOn:["blur"]});
var sprytextarea1 = new Spry.Widget.ValidationTextarea("sprytextarea1", {validateOn:["blur"]});
var sprytextfield3 = new Spry.Widget.ValidationTextField("sprytextfield3", "none", {validateOn:["blur"], minChars:<?php echo $WAGLOBAL_Captcha_Characters; ?>, maxChars:<?php echo $WAGLOBAL_Captcha_Characters; ?>});
var sprytextfield4 = new Spry.Widget.ValidationTextField("sprytextfield4", "none", {validateOn:["blur"]});
//-->
</script>
your form online does not contain the cpatcha form element, the form is probably not submitting because you have not removed the code to validate the captcha element:
$WAFV_Errors .= WAValidateLE(((isset($_POST["Security_code"]))?strtolower($_POST["Security_code"]):"") . "",((isset($_SESSION["captcha_1"]))?strtolower($_SESSION["captcha_1"]):"") . "",true,4);