Please check My code

<?php
if ($_POST['submit']) {
    $name = $_POST['name'];
	$email = $_POST['email'];
	$subject = $_POST['subject'];
	$message = $_POST['message'];
	$cap = $_POST['captcha'];
    session_start();
	if($cap!=$_SESSION["code"])
		{
			//$_GLOBALS['message']="Captcha is wrong";
			echo "<font color='#FF0000' style='background:#fff'>Captcha is wrong</font>";
		}
		else if(empty($_REQUEST['name'])||empty ($_REQUEST['email'])||empty ($_REQUEST['subject'])||empty ($_REQUEST['message']))
	    {
			$_GLOBALS['message']="Fields are empty";
			echo "<font color='#FF0000' style='background:#eeeeee; width:100%;height:30px;'>Please fill in all required fields</font>";
		}
		else
		{
		$formcontent="Dear Representator \n This Email Sent from  $name , $name have Pre-Sales Questions is that \n
		Message:\n $message";

	/*$recipient = "yasir_raza2000@hotmail.com";
	//$recipient =$email;
	$subject = "WRGCODER TECHNOLOGY LAHORE";
	$subject2 = "You are Successfully Send Email";*/

	$mailheader = "From: $email \r\n";
	// send email
    mail("yasir196@gmail.com",$subject,$formcontent,$mailheader) or die("Error!");
	//mail($recipient,$subject, $formcontent, $mailheader) or die("Error!");
	echo "<font color='#009900'><b>Your Message sent successfully</b></font>";


		}

}
?>


<form id="commentForm" name="contact" action="index.php" method="post" class="contact-form">
<input name="name" type="text" placeholder="Name" class="required" />
<input name="email" type="text" placeholder="Email Address" class="required email"/>
<input name="subject" type="text" placeholder="Subject" class="required"/>
<textarea name="message" rows="5"  placeholder="Enter your message here." class="required"></textarea>
<img src="captcha.php" style="text-align:center" />
<input name="captcha" type="text" placeholder="Enter Image Text" class="required">
<input type="submit" name="submit" value="Send" class="send-btn" />
</form>