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banner[number++] = '<a href="http://emilyharperfan.com"><img src="http://img.photobucket.com/albums/v66/karrie/etlove/banners/emilyharperfan.gif" height="90" width="728" alt="EmilyHarperFan.com" title="EmilyHarperFan.com" border="0" /></a>'
banner[number++] = '<a href="http://getpassionate.org"><img src="http://img.photobucket.com/albums/v66/karrie/etlove/banners/getpassionate.gif" height="90" width="728" alt="GETpassionate.org" title="GETpassionate.org" border="0" /></a>'
banner[number++] = '<a href="http://adrianbellani.net"><img src="http://img.photobucket.com/albums/v66/karrie/etlove/banners/adrianbellani.gif" height="90" width="728" alt="AdrianBellani.net" title="AdrianBellani.net" border="0" /></a>'

increment = Math.floor(Math.random() * number);

document.write(banner[increment]);