As the others said, you can't.
You can find good examples of HTML-php forms on the web, here's a very useful link that combines HTML with javascript for validation and php for sending the email.
Please check the full article (includes zip example) in the source:
http://www.html-form-guide.com/contact-form/php-email-contact-form.html
HTML:
<form method="post" name="contact_form"
action="contact-form-handler.php">
Your Name:
<input type="text" name="name">
Email Address:
<input type="text" name="email">
Message:
<textarea name="message"></textarea>
<input type="submit" value="Submit">
</form>
JS:
<script language="JavaScript">
var frmvalidator = new Validator("contactform");
frmvalidator.addValidation("name","req","Please provide your name");
frmvalidator.addValidation("email","req","Please provide your email");
frmvalidator.addValidation("email","email",
"Please enter a valid email address");
</script>
PHP:
<?php
$errors = '';
$myemail = 'yourname@website.com';//<-----Put Your email address here.
if(empty($_POST['name']) ||
empty($_POST['email']) ||
empty($_POST['message']))
{
$errors .= "\n Error: all fields are required";
}
$name = $_POST['name'];
$email_address = $_POST['email'];
$message = $_POST['message'];
if (!preg_match(
"/^[_a-z0-9-]+(\.[_a-z0-9-]+)*@[a-z0-9-]+(\.[a-z0-9-]+)*(\.[a-z]{2,3})$/i",
$email_address))
{
$errors .= "\n Error: Invalid email address";
}
if( empty($errors))
{
$to = $myemail;
$email_subject = "Contact form submission: $name";
$email_body = "You have received a new message. ".
" Here are the details:\n Name: $name \n ".
"Email: $email_address\n Message \n $message";
$headers = "From: $myemail\n";
$headers .= "Reply-To: $email_address";
mail($to,$email_subject,$email_body,$headers);
//redirect to the 'thank you' page
header('Location: contact-form-thank-you.html');
}
?>