How can I load this text into a div?

So I've got a function in PHP. If no records are found as a result of a SELECT statement, then right now, the syntax I'm working on has this:

echo "We were unable to match the info you provided.";

I want to instead, load some text via JQuery into a div. Right now, I've got this:

echo "<script>$('#header_text').html('We were unable to match the information you provided.\n Please try again.');</script>";

It's not working. I think I know why in that what I've got currently is something that's put in motion by an action of some kind. A click, a button - something. Without that "event," I don't have anything.

Let me know if that's accurate and, if you would, also tell me how I can use JQuery to load some new text into the <div> rather than simply echoing a message.

Thanks!