How to embed variable value in sqldatasource session parameter in c#

I want to question how to embed variable value in sqldatasource session parameter in c#. I use 3.5 dotNet framework. This is mycode:

default.aspx:


<asp:SqlDataSource ID="SqlDataSource1" runat="server"
ConnectionString="<%$ ConnectionStrings:Ora2011 %>"
ProviderName="<%$ ConnectionStrings:Ora2011.ProviderName %>"
SelectCommand="SELECT ID, CATEGORY_NAME FROM (:INVENT_CATEGORY)">
<SelectParameters>
<asp:SessionParameter Name="INVENT_CATEGORY" SessionField="INVENT_CATEGORY" Type="String" />
</SelectParameters>
</asp:SqlDataSource>




C#:

protected void Page_Load(object sender, EventArgs e)
{
string table = "V_INVENTORY"
Session["INVENT_CATEGORY"] = table;
}



When i run this program, i get error "invalid table name". Why i can't embed variable into sqldatasource from session parameter. Thanks for your help