How to Dynamically Load User Controls

[abehm]

I have a couple placeholders in which I want to dynamically load user controls into a multi-pageview based on db data.

The database returns the filename of the user control (i.e. UserControl.ascx), and a value (tdr.Page) to determine which placeholder it should load into.
I then use Server.MapPath to get the path to the user control but when it comes down to Load the control I keep getting the error "filepath\usercontrol.ascx is not a valid virtual path". Can anyone please help me solve this problem?

here is the code i am using:

string component = tdr.UserControl;
string componentPath = Server.MapPath(component);
 
switch (tdr.Page)
{
    case "Page1":
    {
        PlaceHolder ph = (PlaceHolder)PageView1.FindControl("Page1PlaceHolder");
        ph.Controls.Add(Page.LoadControl(componentPath)); //where I get the error
         break;
    }
    case "Page2":
    {
        PlaceHolder ph = (PlaceHolder)PageView2.FindControl("Page2PlaceHolder");
        ph.Controls.Add(Page.LoadControl(componentPath)); //error
        break;
    }
}