What are the header contents to be sent in the php mail function to differentiate between a text mail and html mail..!

The Normal mail function in php is the

mail($to,$subject,$message,$headers);

Common Header Part
==================
$headers = "From: Our Company <company@ourcompany.com>\n";
$headers .= "Reply-To: Our Company <company@ourcompany.com>\n";
$headers .= "MIME-Version: 1.0\n";
$headers .= "Content-Type: multipart/alternative; boundary=\"$mime_boundary\"\n";


so if we want to send a text mails we need to send the $header content as ..

$message = "--$mime_boundary\n";
$message .= "Content-Type: text/plain; charset=UTF-8\n";
$message .= "Content-Transfer-Encoding: 8bit\n\n";

and while in case of sending HTML mails

$message .= "--$mime_boundary\n";
$message .= "Content-Type: text/html; charset=UTF-8\n";
$message .= "Content-Transfer-Encoding: 8bit\n\n";