sitemap : multiple node to same page with dynamic parameters

i have 2 sitemap Nodes linked to same page :

<siteMapNode url="javascript:void(1);" title="title1"> <siteMapNode url="~/Folder1/title1/Service.aspx?param1=A"/> </siteMapNode> <siteMapNode url="javascript:void(2);" title="title2" > <siteMapNode url="~/Folder1/title1/Service.aspx?param1=B"/> </siteMapNode> i use a linkBtn to redirect to page : (first Node )
<asp:LinkButton ID="btnService" runat="server" PostBackUrl='<%# "~/Folder1/title1/Service.aspx?param1=A&param2="+ Eval("ID")+"&param3="+Eval("Name_ID")%>'> get services </asp:LinkButton> and another one with other params to redirect to second node ,
but when it redirects , it doesn't take in consideration sitemap
Go to the complete details ...