Contact Form Using PHP

<?php

if(isset($_POST['full_name'])) {
	if($_POST['full_name'] != '' && $_POST['email'] != '') {
		$headers = 	'From: ' . $_POST['full_name'] . '<' . $_POST['email'] . '>' . "\r\n" .
				'Reply-To: ' 	. $_POST['full_name'] . '<' . $_POST['email'] . '>' . "\r\n" .
				'X-Mailer: PHP/' . phpversion();

		$msg .= 'Name: ' . $_POST['full_name'] . "\r\n";
		$msg .= 'Phone: ' . $_POST['phone'] . "\r\n";
		$msg .= 'Email: ' . $_POST['email'] . "\r\n";
		$msg .= 'Message: ' . $_POST['msg'] . "\r\n";
		if( mail('contact@acme.com', 'Inquiry from Acme Website', $msg, $headers)) {
			echo '<div style="color: green;">Your message has been sent.</div>';
		}
	}
	else {
		echo '<div style="color: red;">Please check fields marked with *.</div>';	
	}
}

?>

<div class="container">
	<div class="row">
	<div class="col-md-12">
		<form name="form1" id="form1" action="" method="post">
			<p>Please fill the following form:</p>
			Name* <br /> <input name="full_name" id="full_name" value="<?php echo $_POST['full_name']; ?>" size="30" /><br />
			Email* <br /> <input name="email" id="email" value="<?php echo $_POST['email']; ?>" size="30" /><br />
			Phone <br /> <input name="phone" id="phone" value="<?php echo $_POST['phone']; ?>" size="30" /><br />
			Message <br /> <textarea name="msg" id="msg" rows="5" style="border: 1px solid #999;" /><?php echo $_POST['msg']; ?></textarea><br />
			<input type="submit" value="  Send  ">
		</form>
	</div>
</div>