Basic User Control Question - Accessing changed variable in user control on containing page

I have a user control inside of an aspx page.
 
User Control:
<%@ Control Language="C#" AutoEventWireup="true" CodeBehind="languageSelector.ascx.cs" Inherits="controls.languageSelector" %> <asp:DropDownList ID="languageDropDown" runat="server" onselectedindexchanged="languageDropDown_SelectedIndexChanged" AutoPostBack="true"> <asp:ListItem Selected="True" Value="en">English</asp:ListItem> <asp:ListItem Value="ja">Japanese</asp:ListItem> <asp:ListItem Value="es">Spanish</asp:ListItem> <asp:ListItem Value="it">Italian</asp:ListItem> <asp:ListItem Value="de">German</asp:ListItem> <asp:ListItem Value="fr">French</asp:ListItem> <asp:ListItem Value=&quo ...