Affiliate banner with javascript help please?

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Hi.
I am an affiliate and use a html editor for placing banners etc..
The usual banners i use are 'ahref....' coded and easy to insert onto the page.
I have some new banners but they are in javascript so when i put the coded in the html format, they do not show.
This is the code :

<script language="javascript" type="text/javascript">
var uri = 'http://track.webgains.com/link.html?wglinkid=13346&wgcampaignid=30843&js=1&c p=' + new String (Math.random()).substring (2, 11);
if(document.referrer){uri+='&origsource='+document .referrer;}
document.write('<sc'+'ript language="JavaScript" type="text/javascript" src="'+uri+'"></sc'+'ript>');
</script>

What do i have to do to get the banner to show on my site using the html code editor?

Any answers much appreciated!!