Accesssing controls in a frame via pagechanging function

I have awizard form with a standard interior wizard page. The wizard page loads a frame from another xaml file that contains that pages controls. In my wizard form cs file in the page changing function I want to access the controls from the wizard page frame. If I add controls directly to the wizard page I can access them, but can't access them from within the frame.

How can I do this?? Below are excerpts from my project. Thanks!!



My Wizard Form... Here is a wizard page that loads a frame.

<wizard:WizardPage PageType="Interior" FontSize="20" FontFamily="Comic Sans MS" CancelButtonVisible="True">

<Frame Background="Transparent" Name="frame1" Source="InvWizSelectItemsFrame.xaml" />

</wizard:WizardPage>

-------------------------------------------------------------

In may wizard form cs file...

private void Inventorywizard_SelectedPageChanging(object sender, WizardSelectedPageChangeEventArgs e)
{
// choose inv products
if (this.Inventorywizard.SelectedPage == SelectItems)
{
validate controls here...
}
}
-------------------------------------------------------------

<Page x:Class="Achiever.InvWizSelectItemsFrame"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:jas="clr-namespace:WPF.JoshSmith.Controls;assembly=WPF.JoshSmith"

Title="Page1" Height="470" Background="Transparent">

Controls...
More controls...

</Page>