I have a template that chooses which macro to show based on a query string.  The below code is wrong though, it still loads both macros even though one is set to invisible.

How do I only load one macro?  I wanted to stick with the WorkoutID=[@id] because of macro cacheing.

 <%  if (String.IsNullOrEmpty(Request.QueryString["id"]))
        {
            RideHome.Visible = true;
            RideDetail.Visible = false;
        }
        else
        {
            RideHome.Visible = false;
            RideDetail.Visible = true;
        }
    %>

    <umbraco:macro  ID="RideHome" Alias="RideHome" runat="server" pageIndex=[@pg] duration=[@duration]></umbraco:Macro>
    <umbraco:macro  ID="RideDetail" Alias="RideDetail" WorkoutID=[@id] runat="server"></umbraco:Macro>