<html><head><title>PHP Mail Sender</title></head><body><?php/* All form fields are automatically passed to the PHP script through the array $HTTP_POST_VARS. */$email = $HTTP_POST_VARS['email'];$subject = $HTTP_POST_VARS['subject'];$message = $HTTP_POST_VARS['message'];/* PHP form validation: the script checks that the Email field contains a valid email address and the Subject field isn't empty. preg_match performs a regular expression match. It's a very powerful PHP function to validate form fields and other strings - see PHP manual for details. */if (!preg_match("/\w+([-+.]\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*/", $email)) { echo "<h4>Invalid email address</h4>"; echo "<a href='javascript:history.back(1);'>Back</a>";} elseif ($subject == "") { echo "<h4>No subject</h4>"; echo "<a href='javascript:history.back(1);'>Back</a>";}/* Sends the mail and outputs the "Thank you" string if the mail is successfully sent, or the error string otherwise. */elseif (mail($email,$subject,$message)) { echo "<h4>Thank you for sending email</h4>";} else { echo "<h4>Can't send email to $email</h4>";}?></body></html>