private void atmlPreviewPanel_XmlDocumentLoaded()
{
btnCollapseAll.Visible = true;
btnExpandAll.Visible = true;
btnFind.Visible = true;
btnWordWrap.Visible = true;
btnSave.Visible = true;
btnPrint.Visible = true;
btnBack.Visible = false;
btnForward.Visible = false;
OnXmlDocumentLoaded();
}