My b2evolution Version: Not Entered

b2evo 2.4.6

Hello,

I subscribed my sitemap to google webmastertools and i recieve a warning for my sitemaps:

All the URLs in your Sitemap have the same priority.
All the URLs in your Sitemap are set to the same priority (not the default priority). Priority indicates the importance of a particular URL relative to other URLs on your site, and doesn't impact your site's performance in search results. If all URLs have the same priority, Google can't tell which are more important. Help Help Problem detected on: Mar 16, 2009

Any suggestions of how to give priorities to pages? and to wich page??

Thanks