[Chris Gwynne]

By prefix I'm assuming you mean...

<script language="javascript" type="text/javascript">
<!--

// -->
</script>

Put your code inside of the JavaScript tags, so your code will look like so...

<script language="javascript" type="text/javascript">
<!--
if (theform.message.value) {
"REQ: " + theform.message.value 
} [else {
"GOT: " + theform.message.value
}] 
// -->
</script>

This is will work assuming your code is right.