[Solved] Multiple nodes with the same URL 'javascript:;' were found. XmlSiteMapProvider requires that sitemap nodes have unique URLs

hello ,

i am following this Role based Authorization and Authentication in ASP.Net

about section 

<siteMapNode url="javascript:;"

what about if i have 3 section 

do i need change it like this 

javascript,
javascript2
javascript3

bec some time when i click  duoble  open new page 

<?xml version="1.0" encoding="utf-8" ?>
<siteMap xmlns="http://schemas.microsoft.com/AspNet/SiteMap-File-1.0" >
 <siteMapNodeurl="" title="Home" description="" roles ="*">
    <siteMapNode url="~/Home.aspx" title="Home" description="Home Page" roles="*" />
    <siteMapNode url="javascript:;" title="Admin" description="Admin Page" roles ="Administrator">
      <siteMapNode url ="~/Admin/Users.aspx" title="Users" description="Users Page"></siteMapNode>
      <siteMapNode url ="~/Admin/Reports.aspx" title="Reports" description="Reports Page"></siteMapNode>
    </siteMapNode>
    <siteMapNode url="~/Contact.aspx" title="Contact" description="Contact Us Page" roles="*" />
 </siteMapNode>
</siteMap>

am getting error