Displaying Random Content On Other Websites

I have a simple script for showing my content (pictures) on other websites, but it generates the content by reading the users date (1-31), and because of that can show only certain amount of content/pictures (31) on a mountly bases. Can I edit this simple script to randomize the way the content is being displayed, so I'll be able to display a greater number of content? Example of the way the content is displayed: [URL]

Code that displays the script:
Code:
<script language="JavaScript" src="[URL]"></script>
Script:

Code:
var msg = new Array();
Stamp = new Date();
today = Stamp.getDate(); .....

function writeTip() {
document.write(msg[today]);
}
document.write(msg[today]);
document.write('<br>[<a <a target=_blank href="[URL]</a>]');