/// <summary>
/// Checks to set if there are any other controls of this type and disables
/// them if so, to insure that there is only one filter on a page.
/// </summary>
protected override void CreateChildControls()
{
if (Filter==null) return;
foreach (Control C in Page.Controls)
if (C.GetType().Name==this.GetType().Name && C!=this) ((DefaultTemplate)C).Disable();
if (Filter.CheckInstalled(Page)) Disable();
}
