If anybody has figured out how to switch themes when selecting from a DropDownList please post the branching logic code and explain which page processing methodology was used, i.e. Page_Load or Page-PreInit.

I'm having a problem changing themes when attempting to select a theme from a DropDownList and hope somebody can suggest what is wrong with the branching logic which seems to be the problem

The .aspx includes EnableTheming="true" in the page directive.

The DDL AutoPostBack="true" and is briefly declared as follows:

value="SelectStyleSheet" selected="True">
    Select A Style Sheet
value="red">
    Red Theme
value="green">
    Green Theme
value="blue">
    Blue Theme

The red theme should be loaded by default.
The following code does not change style sheets when a selection is made from the DDL and I'd like to learn what code should be used so the list item will continue to show 'Select A Style Sheet' after each selection...

void Page_PreInit(object sender, System.EventArgs e) {
    if (ChangeStyleSheet.SelectedValue == "SelectStyleSheet")
        Page.Theme = "red";
    else
        Page.Theme = ChangeStyleSheet.SelectedValue.ToString();
}