Dynamic culture allocation with Master pages

Hey guys,
I have a Master Page that contains a dropdownlist with a language
selection. Upon a new language selected, I would like for the page to
reload in the selected culture. Thus far, I have been able to get my
cultures to change by using changing the value in my web.config file
and reloading the page. That works fine. Now I need to dynamically
change this value using the DDL. So far, I am unable to capture the
newly selected value, which would enable me to change the culture in
PreInit. How can I capture this value?

I have this:

protected void Page_PreInit(object sender, EventArgs e)
{
DropDownList newCulture =
(DropDownList)Master.FindControl("languageDropDownList");
}

and newCulture.SelectedValue still gives me the default value of the
control.

Thanks