Reloading UserControls In MasterPage

[hoyaabanks]

I have 4 usercontrols that are placed in the MasterPage of a particular site. When I execute this function from one of them:

protected void imgBtnPreview_Click(object sender, ImageClickEventArgs e)
{
au = (AdminUser)Session["AdminUser"];
au.IsPreview = true;
Session["AdminUser"] = au;
//ReloadCurrent();
}

I need all three controls to reload and display content based on the new Session Variable, AdminUser.

When You execute an event from one control how do you get the MasterPage to reload other controls that It contains? The MasterPage does not seem to reload otherwise.