If u can add PhP code into that window, then here's some code:
code:
<?php
$textArray[0] = "The first line of text!";
$textArray[1] = "Much text!";
$textArray[2] = "Some text...";
$count = count($textArray);
$count = $count - 1;
$random = rand(0, $count);
echo("<p>" . $textArray[$random] . "</p>");
?>
EDIT: Had done something wrong, fixed now...
I haven't tested it, but it should do the trick.