from http://www.zend.com/zend/tut/using-strings.php:
Another way to write strings, which eliminates the need to escape quotes, is the format known as "Here Document". It is convenient for large amounts of texts. Start a Here Document with <<< followed by an identifier you know is not in the text itself. That identifier is used to mark the end of the text, where it comes on a line of its own, and must start on the first column of that line:
$head = <<<ENDH
<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML//EN">
<head>
<title>Feedback form</title>
</head>
<body bgcolor="white">
<h1 align=center>Feedback form</h1>
ENDH;
the other thing to know is variables are handeled within the here doc. you can have a bunch. each must have a unique identifier. e.g.: <<<ENDH, <<<ENDFooter, <<<ENDReply, etc.
good luck.