silverlight ...使用相对路径的超链接按钮到文件

I am trying to use a hyperlinkbutton in silverlight to enable the user to download a word document. I don't care if a file save as box appears or if the word doc opens in a new browser. I get the error "cannot navigate to locations relative to a page." I've seen it posted that you can do this with the absolute path (www.domain.com/filename.doc) but there's got to be a way to make this relative (/docs/filename.doc). Anyone know how?I am trying to use a hyperlinkbutton in silverl