The JS

// FILE: /ajax/ajax-contact-us.js
jQuery(function($){
	$('.sendEnquiry').click(function(){

		// COLLECT DATA
		var box				=	$('.contactUsBox');
		var sender_name		=	$(box).find('input.name').val();
		var sender_subject	=	$(box).find('input.subject').val();
		var sender_email	=	$(box).find('input.email').val();
		var sender_site		=	$(box).find('input.website').val();
		var sender_message	=	$(box).find('.message').val();


		$.post(ajax_object.ajaxurl, {
			action: 'send_contact_us',
			sender_name: sender_name,
			sender_email: sender_email,
			sender_subject: sender_subject,
			sender_site: sender_site,
			sender_message: sender_message,
			dvashpot: dvashpot,
		}, function(data) {
			var $response		= $(data);
			var success 		= $response.filter('#success').html();
			var error 			= $response.filter('#error').html();

			$('.hcAjax').fadeOut();

			// HANDLE SUCCESS >>
			if(success) {$('.response').text(error).removeClass('error').addClass('success');}

			// HANDLE ERRORS >>
			if(error) {$('.response').text(error).removeClass('success').addClass('error');}


		});

	});
})