message = trim（

_REQUEST [''message'']）;

email_address = trim（

I have a basic feedback form with a submit button.

After the "send" button is clicked, I want the user to be redirected to a
different page that says "Your message has been sent."

How do I do this?

I''ve tried using:

header("Location:http://www.mysite.com/send-confirm.php");

But here''s the error I get:

Warning: Cannot add header information - headers already sent by (output started
at ...

Here''s the code:

<form action= "
<?php
$message = trim($_REQUEST[''message'']);
$email_address = trim($_REQUEST[''email_address'']);
if (empty($message) || empty($email_address))
{
$valid_message = false;
}
else
{
mail( "my email address", "feedback form", $message, "from:
$email_address" );
$valid_message = true;
}
?>"
<input name="email_address" type="text" size="30"/><br />
<textarea name="message" rows="12" cols="23"></textarea><br />
<input type="submit" value="Send">
</form>
<?php
if ($valid_message)
{
echo "valid message";
header("Location:http://www.mysite.com/send-confirm.php");
exit();
}
else
{
echo "invalid message";
}
?>

How do I redirect after the user clicks the send button?

Thanks in advance.

message = trim(

_REQUEST[''message'']);

email_address = trim(